The math is a 100 PE implies a 1% yield. The company could distribute 1% of its value each year to the shareholders in perpetuity. Many started using FCF and PS ratios in recent years, but often this hides the actual profitability of the business. For example, FCF measures typically do not add back equity compensation.. which is obviously highly misleading for tech companies that issue a lot of stock

If a 100 PE company doubles earnings, they will yield 1%, then 2% etc. Of course if they don't pay dividends then this yield is "theoretical", but its the fundamental basis of how to price equities.

Coke (KO) which is a fairly stagnant company is at a 30 PE, while GOOG is at 20. It seems to me that most fund managers these days haven't lived in a time where valuation matters... everything is vastly mispriced for the most part. There are pockets of fair value though, but buying a broad index is a pretty bad idea right now, IMO.

In terms of bonds, they have a market value, but the yield is guaranteed (assuming the issuer doesn't default). If you buy a 1yr bond yielding 3%, and the issuer doesn't default, you will get a 3% return by the end of the next year. It doesn't work the same for bond funds, but this is how it works for individual bonds

you wouldn’t buy an S&P509 ETF until at least how much of a pullback, 30%?

Tip: Don't buy bond funds (mutual and ETFs). Buy the bonds directly, then hold to maturity. This will give you the yield-to-maturity that you are seeking.

The yield is for new buyers. Your bonds, bought when yield are lower, is worth less.

OK, so it could happen if I buy now it would be worth even less due to yields go higher which seems to be the trend.

The market value of a bond will decrease, but the yield at purchase is locked in. But bond funds are different because they are constantly rolling money into new bonds, rather than just buying and holding a given set of bonds.

That depends on whether you want to sell your bonds or hold on to them and enjoy the coupon payments. If its the latter the falling price of the bond is not relevant to you. You can still get hurt by inflation, default, changes in tax laws etc. If you have the spare cash, you could buy the older bond issues on the dips induced by rising interest rates. That's a pretty decent strategy because these old bonds are those that are going to mature sooner, lower the time left, less sensitive are their resale value to further interest rate hikes. This leaves you with the option of selling them without much financial harm in case you are in a situation that you have to.