I don't know and I don't care.Record Stock Market Highs
I view stock market fluctuations as being similar to respiration--in and out with minute pauses between the events.
The record high will be followed by a crash, then a slow eventual rise to a new high. I've been in index funds since 1980, so far so good, but the ride has not ever been smooth for very long--something about risk and reward being proportional.
My bond holdings are about 10 years of my portfolio spending. My SS was delayed to age 70, as a buffer for future inflation and for the steady income since my spending method is a longevity based percentage of each recent annual portfolio value (plus dividends and interest). When the crash does occur, I can see in advance, about how much my next year's income will change. Note how adapting my spending, to each recent annual portfolio value, contributes to portfolio longevity.
A sage has written "Accept what is, and do what you can."
Seems like good advice for the current situation.