Hi,
@Mooseman2000. Fwiw, the question may be obvious, but i'm not the sure the answer is! ;)
Joking aside, all these answers already are giving really good points. Choosing when to invest based on market prices is difficult.
Bonds are a fine way to have a portfolio that dips less in bad times though it rises less in good times, at least where "good times" are defined as "times when the stock market rises." So having some bonds as part of your allocation is great if you want less volatility, more knowledge that tomorrow's portfolio value is similar to today's.
But if you are 100% stocks to date, the question of when to add bonds is trickier. Doing it when stock prices are high is obviously better than when prices are low, so a few months ago is better than now, if you have access to a time machine.
IMHO the best thing to do is ask yourself when you expect to spend the money you're investing. If it's more than 5 years from now (in other words, you're in the accumulation phase, not yet close to FI) my suggestion would be to buy stocks when stock prices are lower than today, and bonds when stock prices are higher than today, until you reach your chosen %.
There's no perfect formula. Most people buy high and sell low. They buy bonds when stocks are falling, the exact opposite of what produces high returns. If you add bonds now, you are moving in the typical direction. My suggestion above is designed to counter that common response, while giving a concrete path to getting bonds eventually.
I'm in FIRE myself and am about 30% bonds vs 70% stock (to be fair, that's half the portfolio; the other half is real estate equity). Even if I was 100% stock, I wouldn't buy bonds now. I may soon sell bonds and buy stock!!
If you'll be investing for several more years, falling stock markets and a still-strong job market make this look like a great time to invest in equity. No one can predict the future, but if you have the Intestinal Fortitude, see if you can hold off on the bonds for now. Anyway, good luck.
One way to get the bonds in while wisely ignoring market prices would be to estimate your years to retirement, choose the bond % you want in retirement, and move there in steady increments. For example, if you guess you're 10 years from retirement and want a 30% bond allocation, add 3% bonds per year.
PS. One really common solution to the "when to rebalance" question is "every year, on the date I chose when I set my plan." Obviously you can set such a plan for the future. Once you have it, rebalance at that time to reach your desired % bonds vs % stocks. Doing this mechanically eliminates emotion-driven decisions, which are usually mistakes when it comes to investing.
