Weighted average coupon rate is at-issue or price-adjusted?

[Carsson3]

When a fund company quotes an end of period weighted average coupon rate for a bond fund, there is no explicit indication online whether the quote is (1) the weighted averge of the at-issue coupon rates of fund holdings, or alternatively (2) the weighted average price adjusted coupon rates of fund holdings.
Asking customer-facing financial company employees this question gets me nowhere in particular. Employees say they do not know, or they seem to guess, since it's easy to pick one alternative or the other based on something less than solid knowledge. Two very large fund companies have given me conflicting answers, which could indicate there is no governmental rule applicable for this context. It is shocking what basic bond concepts fund company employees do not understand at all, with presumably all their BBAs and MBAs (which I do not have).
So I am down to wondering what governmental rule might apply here either way, if there is one, and how to find online the official statement of any such rule. Or at least what agency would promulgate such a rule (if not everyone is already fired).
The usefulness of knowing the answer to this question may be for TIPS funds, where the weighted average price-adjusted coupon is also the buyer's real coupon.

[Beensabu]

Coupon rate is at-issue, I believe. The original "contract" rate that comes with the bond.

For price-adjusted, look at yield-to-maturity.

Edit: From VIPSX notes:

This figure is an estimated yield-to-maturity (YTM) for the fund. It is calculated by adding the trailing 12-month inflation adjustment to the "real" (i.e., before inflation) YTM of the fund. Adding the 12-month inflation adjustment allows the fund's yield to be more directly comparable to those of other bond funds. Investors should recognize that the actual YTM will depend upon the level of inflation experienced going forward.

[Geologist]

The phone representatives are there to answer questions about customer's accounts. At best, they have secondary knowledge of details about how funds work and how various elements of a fund are calculated. Further, few customers care about this. Thus I'm not surprised that you have had trouble with finding out information like this from more than one fund company.

(It could easily be that the only governmentally specified rate associated with bond funds is the SEC yield, which the SEC devised so that there would be a standard calculation for comparing funds as long as you have this value for the same day for each fund.)

[jeffyscott]

The usefulness of knowing the answer to this question may be for TIPS funds, where the weighted average price-adjusted coupon is also the buyer's real coupon.

I don't understand why you think that's useful information, but perhaps you could check what they are using by doing your own calculation. TIPS funds don't have that many holdings to review. Vanguard's short term TIPS fund VTAPX has only 26 holdings, for example.

Could you download or copy the VTAPX holdings from Vanguard to a spreadsheet and then calculate the weighted coupon both ways from that?

[coachd50]

When a fund company quotes an end of period weighted average coupon rate for a bond fund, there is no explicit indication online whether the quote is (1) the weighted averge of the at-issue coupon rates of fund holdings, or alternatively (2) the weighted average price adjusted coupon rates of fund holdings.
Asking customer-facing financial company employees this question gets me nowhere in particular. Employees say they do not know, or they seem to guess, since it's easy to pick one alternative or the other based on something less than solid knowledge. Two very large fund companies have given me conflicting answers, which could indicate there is no governmental rule applicable for this context. It is shocking what basic bond concepts fund company employees do not understand at all, with presumably all their BBAs and MBAs (which I do not have).
So I am down to wondering what governmental rule might apply here either way, if there is one, and how to find online the official statement of any such rule. Or at least what agency would promulgate such a rule (if not everyone is already fired).
The usefulness of knowing the answer to this question may be for TIPS funds, where the weighted average price-adjusted coupon is also the buyer's real coupon.

Edited - in looking up the terms here- I only see information about the weighted average coupon rate being used with mortgage backed securities.

I am unfamiliar with the metric- how is it generally used based on your experience? Which funds?

[Carsson3]

(It could easily be that the only governmentally specified rate associated with bond funds is the SEC yield, which the SEC devised so that there would be a standard calculation for comparing funds as long as you have this value for the same day for each fund.)

A rate is not a yield, so a better word might be chosen there, I would assume. I take your point to be in any case that the SEC yield may be the only government mandated number for the sake of fund comparison. That may be correct and is a good guess, but I would like to really know, and have some strongly supported answer either way from whatever government publication addresses these issues.

[Carsson3]

I don't understand why you think that's useful information, but perhaps you could check what they are using by doing your own calculation. TIPS funds don't have that many holdings to review. Vanguard's short term TIPS fund VTAPX has only 26 holdings, for example.

Could you download or copy the VTAPX holdings from Vanguard to a spreadsheet and then calculate the weighted coupon both ways from that?

Responding to your second paragraph, I have indeed done that download (copy-paste), but not recently. I would not want to have to do it over and over, if I can fully understand what the fund company is publishing.
When buying an individual TIPs bond at issue, the buyer's coupon rate is of course my real rate of return, absent compounding, held to maturity. So I would like to know the coupon return of a TIPs fund in the same way, even though fund buying and selling in the future does present more uncertainties.
My guidelinefor a TIPS fund, or individual TIPs bonds if I bought them, is roughly to buy around a 2% plus weighted average coupon, and sell around 1%.
My problem is that it is not clear enough to me whether the fund companies are publishing the weighted average coupon based on at-issue rates or based on current market price-adjusted rates. Vanguard told me "at-issue", and Fidelity told me "market price-adjusted".
The weighted average at-issue coupon rate would reflect prospective cash flow (messed with by price fluctuations in funds, I think), so there would not be a lot of guidance value in knowing that number for making investment decisions.
So the natural assumption is that the published coupon rates for all bond fund are adjusted for market price. I suppose I need to do another download of a TIPS fund details, but this is useful only at month-end when weighted average coupon rates are reported. My problem has been remembering to do this exactly at that date.
Fund companies need to put up an asterisk *coupon rate adjusted to current market price", or similar, if true.

[jeffyscott]

When buying an individual TIPs bond at issue, the buyer's coupon rate is of course my real rate of return, absent compounding, held to maturity.

I don't think so. If I bought the April 2029, with a 3.875% coupon the cost would have been about 109% of par based on Friday's WSJ quotes. That would, I think, make your "buyers real coupon" about 3.5% . Your real rate of return will not be 3.5%. The actual real yield for that TIPS is about 1.5%. The coupon is just telling you some sort of real cash flow that you will receive.

There's a 2054 TIPS that was selling near par on Friday, the coupon is 2.375%. Since it was at par that is also approximately the "buyer's coupon" and the real yield. Meanwhile there's a 2052 priced at about 56 with a coupon of 0.125%, so that would apparently be a buyer's real coupon of about 0.22% . This really tells you nothing other than the 2054 will pay out much more in coupons than the 2052, both of them have similar real yields of about 2.3%.