POLL: How much rebalancing bonus do you expect?
POLL: How much rebalancing bonus do you expect?
The basic Boglehead is to pick a target asset allocation and then stick with it. But over time, portfolio asset weights will drift from the target. At some point, rebalance back to target. This could be done periodically, like every year, month or day, or by threshold bands, like +/5% or 10%.
For example, if the target portfolio had two funds, Total Stock Market (VTI) and Total Bond Market (BND), and the target was equal weighting, 50/50. Over time, this may drift to 60/40. If you had 10% rebalancing bands, you might rebalance back to 50/50, or maybe partway to 50/50. There's a million different rebalancing schema.
Some refer to a "rebalancing bonus", or rebalancing return, which would be the return from selling the winners and buying the losers.
How much extra return do you expect to get from rebalancing? Note that the poll answers allow for both positive (rebalancing bonus) and negative (rebalancing penalty) responses. If you like, feel free to describe your rebalancing method and explain why you answered the way you did.
For example, if the target portfolio had two funds, Total Stock Market (VTI) and Total Bond Market (BND), and the target was equal weighting, 50/50. Over time, this may drift to 60/40. If you had 10% rebalancing bands, you might rebalance back to 50/50, or maybe partway to 50/50. There's a million different rebalancing schema.
Some refer to a "rebalancing bonus", or rebalancing return, which would be the return from selling the winners and buying the losers.
How much extra return do you expect to get from rebalancing? Note that the poll answers allow for both positive (rebalancing bonus) and negative (rebalancing penalty) responses. If you like, feel free to describe your rebalancing method and explain why you answered the way you did.
Last edited by grayfox on Thu Dec 20, 2012 10:41 am, edited 1 time in total.
 Noobvestor
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Re: How much rebalancing bonus do you expect?
I went with 0 to negative 1, but it could be much worse (more negative) than that. If I really never rebalanced back from equities, I imagine my equityheavierandheavier portfolio will more likely than not do much better than my balanced stock/bond one.
As for me: I rebalance with new money in fits and starts as it comes in, and may or may not if I need to sell things to do it, since a lot of my port is taxable. In theory, I have bands. In practice, I have tax consequences. I haven't hit a problem yet that couldn't be solved with new money added, but may at some point, so we'll see.
As for me: I rebalance with new money in fits and starts as it comes in, and may or may not if I need to sell things to do it, since a lot of my port is taxable. In theory, I have bands. In practice, I have tax consequences. I haven't hit a problem yet that couldn't be solved with new money added, but may at some point, so we'll see.
"In the absence of clarity, diversification is the only logical strategy" = Larry Swedroe
 Random Musings
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Re: How much rebalancing bonus do you expect?
Equities, in the longrun, have outperformed bonds, and the expectations are that they will continue to do so. Hence, on average, you are rebalancing more often from equities to bonds which should diminish returns.
However, if one looks at it from a set allocation point (say 5050 target), it's not the "rebalancing bonus" that is the driver, IMHO. It's more about sticking with your portfolio need of risk in your written investment plan.
RM
However, if one looks at it from a set allocation point (say 5050 target), it's not the "rebalancing bonus" that is the driver, IMHO. It's more about sticking with your portfolio need of risk in your written investment plan.
RM
I figure the odds be fiftyfifty I just might have something to say. FZ
Re: How much rebalancing bonus do you expect?
I voted 'zero to negative one' because most of my rebalancing over the past 25 years has been from stocks to bonds. Since stocks tend to perform better than bonds over the long run, I probably would have had a higher return, but riskier portfolio, if I left the money in stocks. I rebalance to manage risk.
However, when rebalancing between U.S. and foreign stocks, I would expect a 'zero to positive one' percent gain due to the 'buy low, sell high' tendency.
However, when rebalancing between U.S. and foreign stocks, I would expect a 'zero to positive one' percent gain due to the 'buy low, sell high' tendency.
Re: How much rebalancing bonus do you expect?
I expect a bonus of between 1% and 2%. I do not rebalance based on the calendar nor do I use 5% to 10%. Instead, I use the RBD method which seems to work extremely well.
Re: How much rebalancing bonus do you expect?
I voted Approximately 0% as the expected rebalancing return.
Now, I have no doubt that if there are two portfolios, one rebalanced and one not, that they will end up with different results. I don't believe the rebalancing return expost will be zero. But I think the rebalancing return, which I would characterize as a return from a trading strategy, can be positive or negative, and it depends on luck and timing.
I found a paper by Vanguard, Portfolio Rebalancing in Theory and Practice that looked into rebalancing. They conclude that rebalancing subtracts from returns in trending markets and adds to returns in meanreverting markets. If you are in a trending market, the rebalancing strategy that rebalances less often will have higher rebalancing return. For example,10% bands instead of 5%. But if you wait too long before rebalancing and the trend reverses, then you missed out. It all seems to be in the timing.
Now, I have no doubt that if there are two portfolios, one rebalanced and one not, that they will end up with different results. I don't believe the rebalancing return expost will be zero. But I think the rebalancing return, which I would characterize as a return from a trading strategy, can be positive or negative, and it depends on luck and timing.
I found a paper by Vanguard, Portfolio Rebalancing in Theory and Practice that looked into rebalancing. They conclude that rebalancing subtracts from returns in trending markets and adds to returns in meanreverting markets. If you are in a trending market, the rebalancing strategy that rebalances less often will have higher rebalancing return. For example,10% bands instead of 5%. But if you wait too long before rebalancing and the trend reverses, then you missed out. It all seems to be in the timing.
Re: How much rebalancing bonus do you expect?
It doesn't look like there are any votes for 1 to 2%livesoft wrote:I expect a bonus of between 1% and 2%. I do not rebalance based on the calendar nor do I use 5% to 10%. Instead, I use the RBD method which seems to work extremely well.
Re: How much rebalancing bonus do you expect?
^ I didn't say I voted, did I?
Re: How much rebalancing bonus do you expect?
One of the reasons I created this poll was that I saw this old thread Opportunistic Rebalancing: A New Paradigm from 2008 had been revived
Now if you study Modern Finance in university, one of the results is that return of a portfolio is equal to the weighted sum of the returns of the components.
Rp = w1*R1 + w1*R2 + w3*R3 + ... wn*Rn
As far as I have seen up to this point, balancing return is not part of the modern finance theory. They don't add in rebalancing bonus to Rp. When you solve for the efficient frontier (EF), the highest returning portfolio is 100% of the highest returning asset. The lowest returning portfolio is 100% of the lowest returning asset.
There can be portfolios on the EF that have lower volatility than the least volatile asset. This seemingly magical result is from uncorrelated assets. But there are no portfolios on the efficient frontier that have higher return than the highest return asset.
That's why I would call the rebalancing return profit & loss from trading.
Now if you study Modern Finance in university, one of the results is that return of a portfolio is equal to the weighted sum of the returns of the components.
Rp = w1*R1 + w1*R2 + w3*R3 + ... wn*Rn
As far as I have seen up to this point, balancing return is not part of the modern finance theory. They don't add in rebalancing bonus to Rp. When you solve for the efficient frontier (EF), the highest returning portfolio is 100% of the highest returning asset. The lowest returning portfolio is 100% of the lowest returning asset.
There can be portfolios on the EF that have lower volatility than the least volatile asset. This seemingly magical result is from uncorrelated assets. But there are no portfolios on the efficient frontier that have higher return than the highest return asset.
That's why I would call the rebalancing return profit & loss from trading.
 Noobvestor
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Re: How much rebalancing bonus do you expect?
That's a really interesting result. I almost wonder if the next poll should be something like: do you expect the bond component of your portfolio to increase returns? I'd never presumed it might in my case, but figured it could actually do that in the case of someone with 8090% stocks, say, and longterm bonds  i.e. I thought perhaps, without ever bothering to run numbers, that some portfolios might indeed beat their topasset return if they had something volatile enough to facilitate rebalancing at extreme points.grayfox wrote:One of the reasons I created this poll was that I saw this old thread Opportunistic Rebalancing: A New Paradigm from 2008 had been revived
Now if you study Modern Finance in university, one of the results is that return of a portfolio is equal to the weighted sum of the returns of the components.
Rp = w1*R1 + w1*R2 + w3*R3 + ... wn*Rn
As far as I have seen up to this point, balancing return is not part of the modern finance theory. They don't add in rebalancing bonus to Rp. When you solve for the efficient frontier (EF), the highest returning portfolio is 100% of the highest returning asset. The lowest returning portfolio is 100% of the lowest returning asset.
There can be portfolios on the EF that have lower volatility than the least volatile asset. This seemingly magical result is from uncorrelated assets. But there are no portfolios on the efficient frontier that have higher return than the highest return asset.
That's why I would call the rebalancing return profit & loss from trading.
"In the absence of clarity, diversification is the only logical strategy" = Larry Swedroe
Re: POLL: How much rebalancing bonus do you expect?
I voted approximately zero.
I have doubts about rebalancing back to a DIY AA. Is there any reason to believe an initially arbitrary AA is efficient or will be efficient over the long run?
I have doubts about rebalancing back to a DIY AA. Is there any reason to believe an initially arbitrary AA is efficient or will be efficient over the long run?

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Re: POLL: How much rebalancing bonus do you expect?
GrayFox,
I have not taken any university level finance classes. But based on my reading of Boglehead books, I think I disagree with what you posited. The return of a portfolio cannot simply be the weighted average return of the components. The compounded return of the portfolio is always less than the weighted average annual return of the components due to portfolio volatility. In fact, the more you can dampen portfolio volatility through investing in multiple asset classes, the closer the compounded return will be to the average annual return of the components. The positive effect of dampened portfolio volatility on annualized (compounded) returns is what I would view as the rebalancing bonus.
The potential benefit of adding an asset class to a portfolio depends on more than its return. It depends on expected return, correlation to other portfolio components, volatility. Curious to hear your thoughts.
Dave
I have not taken any university level finance classes. But based on my reading of Boglehead books, I think I disagree with what you posited. The return of a portfolio cannot simply be the weighted average return of the components. The compounded return of the portfolio is always less than the weighted average annual return of the components due to portfolio volatility. In fact, the more you can dampen portfolio volatility through investing in multiple asset classes, the closer the compounded return will be to the average annual return of the components. The positive effect of dampened portfolio volatility on annualized (compounded) returns is what I would view as the rebalancing bonus.
The potential benefit of adding an asset class to a portfolio depends on more than its return. It depends on expected return, correlation to other portfolio components, volatility. Curious to hear your thoughts.
Dave
Re: POLL: How much rebalancing bonus do you expect?
At this point I will not be making any rebalancing decisions now. My IPS allows me to make rebalancing decisions up to 1 quarter past the end of the year (Mar 31) if rebalancing is not indicated at the end of the year. I will be in postponement mode from JanMar31, just like last year.
PartOwner of Texas 

“The CMHthe Cost Matters Hypothesis is all that is needed to explain why indexing must and will work… Yes, it is that simple.” John C. Bogle
Re: POLL: How much rebalancing bonus do you expect?
I agree with GrayFox.
Re: POLL: How much rebalancing bonus do you expect?
The ideal is to build a portfolio which will deliver, say, 8% per year with zero volatility. Then your planning is straightforward.
In the real world the portfolio SD is going to cause the portfolio return to fall below 8%, so we try to minimize deviations from 8% in order to keep our plan on track.
But there's no way a portfolio made up of a 6% class and an 8% class is going to have higher portfolio return than a portfolio made up of only the 8% class. I'm looking backward here.
That said, it is possible the 6/8 combo has better riskadjusted return but it will never equal the 8% performance of the single class portfolio.
In the real world the portfolio SD is going to cause the portfolio return to fall below 8%, so we try to minimize deviations from 8% in order to keep our plan on track.
But there's no way a portfolio made up of a 6% class and an 8% class is going to have higher portfolio return than a portfolio made up of only the 8% class. I'm looking backward here.
That said, it is possible the 6/8 combo has better riskadjusted return but it will never equal the 8% performance of the single class portfolio.
Re: POLL: How much rebalancing bonus do you expect?
Doing a full backwardlooking meanvariance optimization the only inputs are the returns and the weights for each investment. The interaction among the classes/investments is derived from the returns.
In a roundabout way you can see why backwardlooking analyses have significant limitations.
That's not to say crystal balls don't have limitations, but...
In a roundabout way you can see why backwardlooking analyses have significant limitations.
That's not to say crystal balls don't have limitations, but...
Dave
The portfolio return is the sum of the weighted returns of the individual classes.
The returns of the individual classes are determined at the end of the period, after each class SD has been accounted for (rolled up into the class return)...and consequently rolled up into the portfolio return. IOW, for return purposes, the SD has already been accounted for and is thus irrelevant...that's why all the interactive stuff doesn't matter when calculating portfolio return.
I think everything you stated after your denial of how portfolio return is determined is basically true, if you step back and look at everything after the fact you'll see what I mean.
Gratis.
The returns of the individual classes are determined at the end of the period, after each class SD has been accounted for (rolled up into the class return)...and consequently rolled up into the portfolio return. IOW, for return purposes, the SD has already been accounted for and is thus irrelevant...that's why all the interactive stuff doesn't matter when calculating portfolio return.
I think everything you stated after your denial of how portfolio return is determined is basically true, if you step back and look at everything after the fact you'll see what I mean.
Gratis.
Re: POLL: How much rebalancing bonus do you expect?
Not true. Suppose I have two investments that have an expected return of 8% but one has twice the volatility of the other. I open two accounts, one with each investment, and wait long enough, say, 30 or 40 years. Both accounts will be up 8%; that's what expected return means. In the meantime, one account will have moved up and down twice as much as the other, but the end result will be the same.Random Walker wrote: The compounded return of the portfolio is always less than the weighted average annual return of the components due to portfolio volatility.
Dave
Now let's suppose that the investments both have really high volatility but they happen to have a 1.0 negative correlation with each other so that when one zigs the other zags. At the end of the long time period, both investments will be up 8%, no more no less, but if I plot the total of the two investments for each year, it will be a nice smooth straight line instead of moving up and down on either side of the 8% line.
Volatility has no effect on the expected value of investments over a long term; Grayfox is absolutely correct. On the other hand, reducing volatility means that any year's returns will be closer to the long term expected value but the expected value itself won't change.
 Dale_G
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Re: POLL: How much rebalancing bonus do you expect?
I have run the numbers on the effect of rebalancing my accounts from 2002 through mid 2012. It can be a bit tedious accounting for dividends, but I am quite confident of the numbers. The rebalancing benefit averaged about 0.73% of the portfolio value per year based on round trip transactions. My asset allocation was 50/50 and I maintained fairly tight rebalancing bands.
It was not much fun rebalancing into the decline of 2008/2009, but the "bonus" eventually realized made up for some of the discomfort.
Volatility can be your friend, but only if you rebalance.
Dale
It was not much fun rebalancing into the decline of 2008/2009, but the "bonus" eventually realized made up for some of the discomfort.
Volatility can be your friend, but only if you rebalance.
Dale
Volatility is my friend
Re: POLL: How much rebalancing bonus do you expect?
I wonder what the bonus would be for someone who rebalanced on the best day for rebalancing of the year each year. Would that not set an upper bound for a rebalancing bonus for the onceayear rebalancer? Would that not be a number to strive for? I suppose it might depend on stock:bond ratio as well.
Re: POLL: How much rebalancing bonus do you expect?
Rebalancing does better when you have two volatile assets with similar returns, as we had with stocks and bonds over the past ten years. If stocks do substantially better than bonds, rebalancing is likely to lower returns.Dale_G wrote:I have run the numbers on the effect of rebalancing my accounts from 2002 through mid 2012. It can be a bit tedious accounting for dividends, but I am quite confident of the numbers. The rebalancing benefit averaged about 0.73% of the portfolio value per year based on round trip transactions. My asset allocation was 50/50 and I maintained fairly tight rebalancing bands.
Re: POLL: How much rebalancing bonus do you expect?
What you are talking about is that the arithmetic mean is less than the geometric mean when there is volatility. That is true even for one asset. For example, if you have twelve monthly returns, take the arithmetic mean, and get 5%. The geometric mean will be less than 5%, unless every month was exactly 5%, i.e. no volatility. Any variation will give lower geometric return.Random Walker wrote:GrayFox,
I have not taken any university level finance classes. But based on my reading of Boglehead books, I think I disagree with what you posited. The return of a portfolio cannot simply be the weighted average return of the components. The compounded return of the portfolio is always less than the weighted average annual return of the components due to portfolio volatility. In fact, the more you can dampen portfolio volatility through investing in multiple asset classes, the closer the compounded return will be to the average annual return of the components. The positive effect of dampened portfolio volatility on annualized (compounded) returns is what I would view as the rebalancing bonus.
The potential benefit of adding an asset class to a portfolio depends on more than its return. It depends on expected return, correlation to other portfolio components, volatility. Curious to hear your thoughts.
Dave
And, yes, the theory is to minimize volatility at some return. Calculate the minimum volatility across the range of returns, and that is the efficient frontier. The surprising thing is that you can get portfolio with lower volatility than the least volatile asset. So 10/90 stocks/bonds might be lower volatility than 0/100, due to lack of correlation.
Re: POLL: How much rebalancing bonus do you expect?
I calculated the return 1) without rebalancing and 2) with daily rebalancing for a Harry Browne portfolio for 2011. The portfolio with daily rebalancing had 0.89% higher return. But I only looked at one year, nor did I look at other rebalancing rules.Dale_G wrote:I have run the numbers on the effect of rebalancing my accounts from 2002 through mid 2012. It can be a bit tedious accounting for dividends, but I am quite confident of the numbers. The rebalancing benefit averaged about 0.73% of the portfolio value per year based on round trip transactions. My asset allocation was 50/50 and I maintained fairly tight rebalancing bands.
It was not much fun rebalancing into the decline of 2008/2009, but the "bonus" eventually realized made up for some of the discomfort.
Volatility can be your friend, but only if you rebalance.
Dale
The Vanguard paper found that in trending markets you get a negative rebalancing return and in mean reverting markets you get a positive rebalancing return. If you went from 2007 to 2010, there was some mighty mean reversion.
As I said earlier, I have no doubt that, expost, you can measure a positive rebalancing return if you time it well. But that has nothing to do with portfolios. You can get it with one security. Suppose IBM returned 10% in 2012. Well if it fluctuated in price, I might have got 12% from that stock just by timing my transactions. I could have sold when it rose, and bought back more shares when it fell. Or even without ever selling, if I'm added new contributions, just buying on dips.
I just don't know if you can say in advance if you will see a bonus or a penalty from rebalacning.
Re: How much rebalancing bonus do you expect?
Diminish returns as compared to what? It is true that the unrebalanced portfolio could do better than the rebalanced one, but only at the expense of increased risk. A rebalanced portfolio can still beat the arithmetic mean return of the unrebalanced portfolio.Random Musings wrote:Equities, in the longrun, have outperformed bonds, and the expectations are that they will continue to do so. Hence, on average, you are rebalancing more often from equities to bonds which should diminish returns.
However, if one looks at it from a set allocation point (say 5050 target), it's not the "rebalancing bonus" that is the driver, IMHO. It's more about sticking with your portfolio need of risk in your written investment plan.
RM
Here is a quote from an old EF article.
"Only when long term return differences among asssets exceed 5 percent do nonrebalanced portfolios provide superior returns, and then only at the cost of increased risk"
I recommend it:
http://www.efficientfrontier.com/ef/197/rebal197.htm
and:
http://www.efficientfrontier.com/ef/996/rebal.htm
http://www.efficientfrontier.com/ef/797/rebal797.htm
malcolm

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Re: POLL: How much rebalancing bonus do you expect?
I'm not really buying what I'm reading here. I certainly could be wrong. But it seems to me that the return of a REBALANCED portfolio cannot simply be the weighted average of the individual components. One needs to look at dollar weighted returns, not simply time weighted. That is the whole potential benefit of rebalancing: buying relatively low and selling relatively high at the asset class level.
If I am wrong, please continue to convince me. I want to understand this stuff. So far though I'm sticking with compounded return less than average annual. And the goal of multiasset class investing with rebalancing is to get the annualized return closer to the average annual return. But need to look at dollar weighted, not just time weighted. Thanks.
Dave
If I am wrong, please continue to convince me. I want to understand this stuff. So far though I'm sticking with compounded return less than average annual. And the goal of multiasset class investing with rebalancing is to get the annualized return closer to the average annual return. But need to look at dollar weighted, not just time weighted. Thanks.
Dave
Re: POLL: How much rebalancing bonus do you expect?
Oh, my! Rebalancing into a trending market. Rebalancing into a reverting market.
When will we ever run out of lipstick for the pig of market timing?
Over the last decade, suppose you invested the same amount monthly into a 50/50 mix of stocks and bonds.
1. You invested and did not rebalance.
2. You rebalanced monthly to keep your allocation at 50/50.
Option 2, continuous rebalancing, is superior to the tune of about 0.3% per year.
In my view, you may never rebalance, and perhaps see your portfolio AA drift to higher returns (and higher risks). Or, you may continually rebalance and see a lower risk and probably better returns.
Anything in between is market timing.
Keith
When will we ever run out of lipstick for the pig of market timing?
Over the last decade, suppose you invested the same amount monthly into a 50/50 mix of stocks and bonds.
1. You invested and did not rebalance.
2. You rebalanced monthly to keep your allocation at 50/50.
Option 2, continuous rebalancing, is superior to the tune of about 0.3% per year.
In my view, you may never rebalance, and perhaps see your portfolio AA drift to higher returns (and higher risks). Or, you may continually rebalance and see a lower risk and probably better returns.
Anything in between is market timing.
Keith
Déjà Vu is not a prediction
 Aptenodytes
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Re: POLL: How much rebalancing bonus do you expect?
Rebalancing, for me, is a risk management strategy, not an optimization strategy. If I don't rebalance my risk exposure gets off. So the more relevant question for me, not necessarily everyone, is how much lower is the probability of a catastrophic loss if I rebalance? I see that benefit as very large.
I realize risk and return are two blades of the same scissors, but when I rebalance I am thinking risk more than return. Seems at a minimum you'd want to look at the return bonus and the risk benefit, not just one.
In any event the counterfactual is a bit bizarre. Having chosen an AA why wouldn't you rebalance to maintain it?
I realize risk and return are two blades of the same scissors, but when I rebalance I am thinking risk more than return. Seems at a minimum you'd want to look at the return bonus and the risk benefit, not just one.
In any event the counterfactual is a bit bizarre. Having chosen an AA why wouldn't you rebalance to maintain it?
Re: POLL: How much rebalancing bonus do you expect?
That's exactly what I said. Rebalanced portfolio, by buying and selling, will end up with a different return than simply holding a portfolio. It could be higher or lower. In other words, the rebalancing return can be positive or negative.Random Walker wrote:I'm not really buying what I'm reading here. I certainly could be wrong. But it seems to me that the return of a REBALANCED portfolio cannot simply be the weighted average of the individual components.
Dave
But it has nothing to do with modern portfolio theory. It is explained by old fashioned buying low and selling high.
If stocks go lower after you sell stocks to rebalance, you will have higher return than holding. < rebalancing bonus
If stocks continues higher after you sell to rebalance, you will have lower return than holding. < rebalancing penalty
Here is a link to Modern portfolio theory. You will not see anything about a rebalancing bonus on that page. Below is the formula for expected return from that page, the weighted sum of the components.
Last edited by grayfox on Mon Dec 24, 2012 10:45 am, edited 1 time in total.
Re: POLL: How much rebalancing bonus do you expect?
That's the bigger picture.Aptenodytes wrote:Rebalancing, for me, is a risk management strategy, not an optimization strategy. If I don't rebalance my risk exposure gets off. So the more relevant question for me, not necessarily everyone, is how much lower is the probability of a catastrophic loss if I rebalance? I see that benefit as very large.
I realize risk and return are two blades of the same scissors, but when I rebalance I am thinking risk more than return. Seems at a minimum you'd want to look at the return bonus and the risk benefit, not just one.
In any event the counterfactual is a bit bizarre. Having chosen an AA why wouldn't you rebalance to maintain it?
If I have a target portfolio that is 30/70, then it make sense to maintain that by rebalancing. For whatever reasons, I chose 30/70, and it wouldn't make sense to have 20/80, 50/00, 0/100 or anything else. Ideally, that would mean rebalancing as often as practical. With mutual funds that might be every two months because of frequent trading rules.
But it seems that some are advising, "No, delay rebalancing for a couple of years. Then you will get the maximum rebalancing bonus." I can cite books that recommend that. I've also read advice to choose 50/50 asset allocation because it will maximize the rebalancing bonus.
So the poll is to see how many here believe that they can get a rebalancing bonus by timing their rebalancing moves. From the poll, it looks like over 40% of respondents believe that they will get a rebalancing bonus by welltimed rebalancing.
BTW, the poll is set up so that you can change your vote, if anyone is having second thoughts about the rebalancing bonus.
Re: POLL: How much rebalancing bonus do you expect?
If they're that smart, why don't they unbalance?So the poll is to see how many here believe that they can get a rebalancing bonus by timing their rebalancing moves.
Keith
Déjà Vu is not a prediction

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Re: POLL: How much rebalancing bonus do you expect?
Gray fox,
Thanks for the comments. I'm sure I'm going to learn something from this. But I'm still disagreeing. The equation you post is the expected return ex ante of a portfolio comprised of individual components. It does not account for potential affects of internal rebalancing. I agree that if you start at time point 1 and finish at time point 2, then the portfolio return of a portfolio with no additions/subtractions and no rebalancing will be the weighted average of the components.
But I believe portfolio volatility will have a huge effect on compounded annualized returns and that volatility will be dampened by multi asset class investing. So I guess what I'm saying is the following. Multi asset class investing will dampen portfolio volatility and bring compounded return closer to average annual return. Rebalancing will maintain the risk profile and can have positive or negative effect on returns depending on the course of market, momentum, reversion to mean. Ok now decipher this and straighten me out. Thanks.
Dave
Thanks for the comments. I'm sure I'm going to learn something from this. But I'm still disagreeing. The equation you post is the expected return ex ante of a portfolio comprised of individual components. It does not account for potential affects of internal rebalancing. I agree that if you start at time point 1 and finish at time point 2, then the portfolio return of a portfolio with no additions/subtractions and no rebalancing will be the weighted average of the components.
But I believe portfolio volatility will have a huge effect on compounded annualized returns and that volatility will be dampened by multi asset class investing. So I guess what I'm saying is the following. Multi asset class investing will dampen portfolio volatility and bring compounded return closer to average annual return. Rebalancing will maintain the risk profile and can have positive or negative effect on returns depending on the course of market, momentum, reversion to mean. Ok now decipher this and straighten me out. Thanks.
Dave
Re: POLL: How much rebalancing bonus do you expect?
I don't disagree with anything you just wrote. So I'm not sure what you disagreeing about. Are you disagreeing that we agree?Random Walker wrote:Gray fox,
Thanks for the comments. I'm sure I'm going to learn something from this. But I'm still disagreeing. The equation you post is the expected return ex ante of a portfolio comprised of individual components. It does not account for potential affects of internal rebalancing. I agree that if you start at time point 1 and finish at time point 2, then the portfolio return of a portfolio with no additions/subtractions and no rebalancing will be the weighted average of the components.
But I believe portfolio volatility will have a huge effect on compounded annualized returns and that volatility will be dampened by multi asset class investing. So I guess what I'm saying is the following. Multi asset class investing will dampen portfolio volatility and bring compounded return closer to average annual return. Rebalancing will maintain the risk profile and can have positive or negative effect on returns depending on the course of market, momentum, reversion to mean. Ok now decipher this and straighten me out. Thanks.
Dave
Re: POLL: How much rebalancing bonus do you expect?
They do. On RBDs. They get a better return than Wellington, but have more bonds in their portfolios.umfundi wrote:If they're that smart, why don't they unbalance?So the poll is to see how many here believe that they can get a rebalancing bonus by timing their rebalancing moves.
Keith
Re: POLL: How much rebalancing bonus do you expect?
Look at the Vanguard paper cited above. Look at Table 3, the one that contains results for a no reblance condition.
Rebalancing does win in average return, by an astonishing, massive, .014%. (I hope that had good numerical accuracy control in their simulation.)
Reblancing does somewhat better when you look at volatility. All of the rebalancing conditions have around 10% volatility as versus 12% for a pure buy and hold strategy.
My conclusion: rebalance for less jumping around, not for a better return. If I can get the same return with less volatility why not go for it? If I want better returns, as usual, I'll have to take on more risk.
Rebalancing does win in average return, by an astonishing, massive, .014%. (I hope that had good numerical accuracy control in their simulation.)
Reblancing does somewhat better when you look at volatility. All of the rebalancing conditions have around 10% volatility as versus 12% for a pure buy and hold strategy.
My conclusion: rebalance for less jumping around, not for a better return. If I can get the same return with less volatility why not go for it? If I want better returns, as usual, I'll have to take on more risk.
Re: POLL: How much rebalancing bonus do you expect?
In theory, rebalancing could results in a total higher return than any return from the sub asset class.
I still remember an interesting question:"how do you make money from a random walking stock market, which has zero expected return"
So if you have 2 asset class:
1. cash, stable value, no interest, expected return is zero
2. a stock, random walking, expected return is zero
if you keep the cash and stock to be 50/50 (or any other fixed ratio) and keep rebalancing every time the stock price changes. ignoring any transaction fees, you are guaranteed to make money whenever the stock price come back to it's original price. you can use Excel to simulate and prove it.
the weighted return thing only applies to portfolios without any transactions. Imagine I can catch all up and downs, I can have a return much higher than the reported annualized return of the specific fund. Rebalancing tells you when to catch the up and downs, so theoretically, can results higher returns than the weighted average of all the sub asset class.
I still remember an interesting question:"how do you make money from a random walking stock market, which has zero expected return"
So if you have 2 asset class:
1. cash, stable value, no interest, expected return is zero
2. a stock, random walking, expected return is zero
if you keep the cash and stock to be 50/50 (or any other fixed ratio) and keep rebalancing every time the stock price changes. ignoring any transaction fees, you are guaranteed to make money whenever the stock price come back to it's original price. you can use Excel to simulate and prove it.
the weighted return thing only applies to portfolios without any transactions. Imagine I can catch all up and downs, I can have a return much higher than the reported annualized return of the specific fund. Rebalancing tells you when to catch the up and downs, so theoretically, can results higher returns than the weighted average of all the sub asset class.
Re: POLL: How much rebalancing bonus do you expect?
I expect upwards of about 1%. But I don't consider it a bonus; just a return from outlandishly out of balance portfolio assets returning to mean post rebalancing. So far it seems to be working.  Tet
Re: POLL: How much rebalancing bonus do you expect?
"Rebalancing equals noise."
John Bogle
John Bogle
Re: POLL: How much rebalancing bonus do you expect?
Bogle never said that.Matigas wrote:"Rebalancing equals noise."
John Bogle
He might have said not to worry about small drifts in your equity ratio and that that formulaic rebalancing with precision is not necessary, but so far as I can find he he never made that exact quote.
Keith
Déjà Vu is not a prediction
Re: POLL: How much rebalancing bonus do you expect?
This paper from 2008 that was posted on another thread has the best information I've seen on rebalancing
Opportunistic Rebalancing
A couple of points:
1. Observe that some periods had negative rebalreturn and some periods had positive rebalreturn. Periods with trending markets had negative rebalreturn; periods with reversals, had positive rebalreturn. Rebalancing can add to return or subtract from return, depending on the market conditions, i.e. trending or meanreverting.
2. The amount of rebalreturn varied with the rebalancing algorithm. It must also vary with the portfolio asset allocation, as well. The paper only looked at one asset allocation, 60/40 stock/bonds.
3. The oftenrecommended annual rebalance with 0% bands does not look like the best method. The paper shows 20% bands with lookinterval of 1 day to 2 weeks was best.
Opportunistic Rebalancing
A couple of points:
1. Observe that some periods had negative rebalreturn and some periods had positive rebalreturn. Periods with trending markets had negative rebalreturn; periods with reversals, had positive rebalreturn. Rebalancing can add to return or subtract from return, depending on the market conditions, i.e. trending or meanreverting.
2. The amount of rebalreturn varied with the rebalancing algorithm. It must also vary with the portfolio asset allocation, as well. The paper only looked at one asset allocation, 60/40 stock/bonds.
3. The oftenrecommended annual rebalance with 0% bands does not look like the best method. The paper shows 20% bands with lookinterval of 1 day to 2 weeks was best.
Last edited by grayfox on Wed Dec 26, 2012 10:39 pm, edited 1 time in total.
Re: POLL: How much rebalancing bonus do you expect?
... of the limited methods that the paper looked at.grayfox wrote:...
3. The oftenrecommended annual rebalance with 0% bands does not look like the best method. The paper shows 20% bands with lookinterval of 1 day to 2 weeks was best. ...
Re: POLL: How much rebalancing bonus do you expect?
[removed by author  didn't read OPs link so my comment wasn't helpful]
Last edited by CaliJim on Wed Dec 26, 2012 10:57 pm, edited 2 times in total.
Re: POLL: How much rebalancing bonus do you expect?
Yes, I believe you have a rebalancing algorithm that is triggered by a large oneday fall in the market. I would categorize that as event driven rebalancing. Not covered by the paper. I guess the theory is that the market overreacts and is likely to rebound within a few days, so it is a behavioral theory.
But it definitely appears that a short lookinterval works best. Check your portfolio once a week to see of it needs rebalancing.
But it definitely appears that a short lookinterval works best. Check your portfolio once a week to see of it needs rebalancing.
Re: POLL: How much rebalancing bonus do you expect?
I think the answer is that bonehead (simply periodic) rebalancing is worth 0.2  0.5% a year in a diversified portfolio.
There is a vocal minority that thinks RBD market timing is rebalancing, and they can do much better than a fraction of a percent.
There is another minority that thinks rebalancing will be negative, because they are prepared to tolerate drift in their AA to higher risk.
My own conclusion is that it is worth for me to pay a professional a low fee to pay attention to details like this, and others. He's a passive manager, but I believe his attention outweighs my inattention.
Keith
There is a vocal minority that thinks RBD market timing is rebalancing, and they can do much better than a fraction of a percent.
There is another minority that thinks rebalancing will be negative, because they are prepared to tolerate drift in their AA to higher risk.
My own conclusion is that it is worth for me to pay a professional a low fee to pay attention to details like this, and others. He's a passive manager, but I believe his attention outweighs my inattention.
Keith
Déjà Vu is not a prediction
Re: POLL: How much rebalancing bonus do you expect?
That's a very interesting paper and it makes sense. But I couldn't tell if it is just a backwardlooking algorithm derived from the data that has a ring of reason dressed as a halo that makes it look useful.grayfox wrote:This paper from 2008 that was posted on another thread has the best information I've seen on rebalancing
Opportunistic Rebalancing
A couple of points:
1. Observe that some periods had negative rebalreturn and some periods had positive rebalreturn. Periods with trending markets had negative rebalreturn; periods with reversals, had positive rebalreturn. Rebalancing can add to return or subtract from return, depending on the market conditions, i.e. trending or meanreverting.
2. The amount of rebalreturn varied with the rebalancing algorithm. It must also vary with the portfolio asset allocation, as well. The paper only looked at one asset allocation, 60/40 stock/bonds.
3. The oftenrecommended annual rebalance with 0% bands does not look like the best method. The paper shows 20% bands with lookinterval of 1 day to 2 weeks was best.
I wonder if there's an easy way to set up an automatic alert that tells you when a rebalance should be triggered based on hitting a 20% band?
Billy
Re: POLL: How much rebalancing bonus do you expect?
Here is what I am thinking:
Without Rebalancing
You want to invest a sum of money for some period. You chose some collection assets for your portfolio. Each asset has an expected return, R_i, and volatility, sigma_i^2. One way or another you select the weights, w_i of each asset. Then you make the investment.
The expected portfolio return R_p is the weighted sum of the asset returns.
The expected volatility of the portfolio, sigma_p^2, is a little more complicated to calculate, because it has to take into account not only the volatility of each asset, but all the covariances between pairs of assets.
At the end of the period, each asset will have some return and volatility. If you held the assets through the whole period, the portfolio return and volatility could be calculated using the same equation above, the weighted sum of the asset returns.
With Rebalancing
Now what happens with rebalancing is that you don't hold through the whole period. You sell some and buy some. You are changing the portfolio partway though the period. The return and volatility of the rebalanced portfolio will be different from the buy and hold. Obviously the difference will depend on the rebalancing algorithm.
Let's call the difference between the buyandhold portfolio and a rebalanced portfolio, the rebalancing return, DELTA. R_r = Rp + DELTA
DELTA is random variable. Depending on your portfolio and rebalancing algorithm, DELTA is drawn from probability distribution with some parameters like mean and variance. As I said above, this mean and variance will depend on the rebalancing algorithm.
DELTA can be positive or negative. We've seen that it tends to be negative in trending markets and positive in mean reverting markets.
Restating the poll question: For some portfolio and rebalancing algorithm, what is the mean value of DELTA, mean(DELTA)? Is it positive, zero or negative?
Another question is: How big is the variance of DELTA, var(DELTA) ?
Since the return of the rebalanced portfolio R_rp = Rp + DELTA, then variance of the rebalanced portfolio equals the var(R_p) + var(DELTA), if R_p and DELTA are independent. This result is from basic statistics. See Variance of Differences of Random Variables
In other words, rebalancing increases the variance of the portfolio by the variance of DELTA.
Without Rebalancing
You want to invest a sum of money for some period. You chose some collection assets for your portfolio. Each asset has an expected return, R_i, and volatility, sigma_i^2. One way or another you select the weights, w_i of each asset. Then you make the investment.
The expected portfolio return R_p is the weighted sum of the asset returns.
The expected volatility of the portfolio, sigma_p^2, is a little more complicated to calculate, because it has to take into account not only the volatility of each asset, but all the covariances between pairs of assets.
At the end of the period, each asset will have some return and volatility. If you held the assets through the whole period, the portfolio return and volatility could be calculated using the same equation above, the weighted sum of the asset returns.
With Rebalancing
Now what happens with rebalancing is that you don't hold through the whole period. You sell some and buy some. You are changing the portfolio partway though the period. The return and volatility of the rebalanced portfolio will be different from the buy and hold. Obviously the difference will depend on the rebalancing algorithm.
Let's call the difference between the buyandhold portfolio and a rebalanced portfolio, the rebalancing return, DELTA. R_r = Rp + DELTA
DELTA is random variable. Depending on your portfolio and rebalancing algorithm, DELTA is drawn from probability distribution with some parameters like mean and variance. As I said above, this mean and variance will depend on the rebalancing algorithm.
DELTA can be positive or negative. We've seen that it tends to be negative in trending markets and positive in mean reverting markets.
Restating the poll question: For some portfolio and rebalancing algorithm, what is the mean value of DELTA, mean(DELTA)? Is it positive, zero or negative?
Another question is: How big is the variance of DELTA, var(DELTA) ?
Since the return of the rebalanced portfolio R_rp = Rp + DELTA, then variance of the rebalanced portfolio equals the var(R_p) + var(DELTA), if R_p and DELTA are independent. This result is from basic statistics. See Variance of Differences of Random Variables
In other words, rebalancing increases the variance of the portfolio by the variance of DELTA.

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Re: POLL: How much rebalancing bonus do you expect?
Gray fox,
Now you're seeing what I was trying to say. Additions and subtractions to the portfolio via rebalancing make it a lot more complicated than just a weighted average return issue. Rebalancing helps in reversion to the mean times and hurts when momentum dominates. Lots of variables . That's probably the best reason to simply use rebalancing for risk control and if there is any extra return, then it's icing on the cake. So returns, correlations, volatility are what matters to the portfolio effects of an asset class. So what do you think of a small CCF component?
Dave
Now you're seeing what I was trying to say. Additions and subtractions to the portfolio via rebalancing make it a lot more complicated than just a weighted average return issue. Rebalancing helps in reversion to the mean times and hurts when momentum dominates. Lots of variables . That's probably the best reason to simply use rebalancing for risk control and if there is any extra return, then it's icing on the cake. So returns, correlations, volatility are what matters to the portfolio effects of an asset class. So what do you think of a small CCF component?
Dave