mwrenn wrote: ↑Sun Jan 22, 2023 2:39 pm
Thanks. But, wouldn't using the larger bond capitalization that includes all bonds (i.e., doesn't restrict to investment grade) be more consistent with holding Sharpe's "market" and result in a more efficient portfolio (i.e., higher return per unit risk)? If not, why?
Mwrenn, welcome to the forum!
While theoretically beautiful, Bill Sharpe's Market Portfolio (global stock-and-bond portfolio) is difficult to
perfectly implement. Actually, this is true of index investing in general. It's probably possible get indexing 95%+ right, but perfection is
most probably out of reach, even for big mutual fund and ETF providers.
Vanguard has switched, over the years, the indices it tacks, for its index funds and ETFs to
float-adjusted indices. But, what's float? That's a good question. Let's refine my question.
What's float, when market liquidity dries up? Not long ago, for a few months in 2020, some index providers stopped publishing bond market index data due to lack of liquidity in the bond market. FTSE, in particular, stopped providing its monthly FTSE World Broad Investment-Grade Bond Index (WorldBIG) fact sheet for three months. You'll be able to find a fact sheet for
July 2020, and for
November 2020, but none in between. So, how is an index fund or ETF supposed to adjust to market weights during such a period? (Answer: it can't).
Also, Vanguard's Total World Bond ETF (BNDW) doesn't track a FTSE index. It tracks the "
Bloomberg Global Aggregate Float Adjusted Composite Index, which is designed to track the market capitalized weights of the global investment-grade bond market and is comprised of the Bloomberg U.S. Aggregate Float Adjusted Index and the Bloomberg Aggregate ex- USD Float Adjusted RIC Capped Index (USD Hedged)" (
source). This is a float-adjusted index, with some caps (I think that the cap significantly affects Japan bonds, due to their gigantic capitalization), and it only includes investment-grade bonds, excluding various special types of bonds like TIPS and floating-rate bonds.
Sharpe's
document linked from his March 2021
blog entry reports that "
the estimated total value of traded bonds and stocks was approximately 180 trillion U.S. Dollars" at the end of December 2020. The accompanying figure "
provides the associated estimates of the relative market values of these asset classes at the time" as percentages:
- 28.2% U.S. stocks
- 21.2% U.S. bonds
- 29.2% non-U.S. bonds
- 21.4% non-U.S. stocks
Bill Sharpe used the FTSE Russel AAAP Calculator for the proportions of global stocks and bonds. So, the AAAP Calculator's estimate for global stocks is
((28.2% U.S. stocks + 21.4% non-U.S. stocks) X 180 trillion U.S. Dollars) = 89 trillion U.S. Dollars. Yet, the
December 2020 factsheet of the FTSE Global All Cap Index, tracked by Vanguard's VT, reports a market capitalization of
66 trillion U.S. Dollars. That's
-25% smaller! My
guess is that the AAAP Calculator
probably includes many assets not included in Vanguard's VT (and BNDW), or it might not use the same float adjustments (or caps). What's
certain is that there are significant differences.
Bill Sharpe only claims, in the linked document, that the percentages are an
estimate of asset weights, implying that they're
not exact measurements.
Why am I writing monthly posts, even though the FTSE Russel AAAP Calculator exists? For many reasons:
- There's no need to register to read my posts.
- The posts provide full transparency with links to published index fact sheets so that readers can verify the numbers (and report mistakes, if any),
- The FTSE Global All Cap Index and the FTSE World Broad Investment-Grade Bond Index seem like good enough representatives of the markets tracked by Vanguard's VT and BNDW ETFs.
- The posts provide the returns of a portfolio composed of two real-world ETFs (VT + BNDW) after fees, instead of synthetic index returns.
- This forum (and any public archive of it) is less likely to completely disappear without trace than the FTSE Russel AAAP Calculator which is only privately accessible by registered users.
Variable Percentage Withdrawal (VPW) | One-ETF Portfolio (VBAL in all accounts) | https://www.bogleheads.org/wiki/Variable_percentage_withdrawal