15% off from what? 15% off the maximum value achieved during a period of unprecedented monetary and fiscal stimulus?
Given the fed reversal, it's looking pretty clear that stocks will fall quite a bit further. Buying equities now is tantamount to fighting the fed.
Timing the market never works, so if you sit out you won't know when to get back in, but the entity with the power to dramatically influence asset prices has broadcast their intentions and is about to undertake actions which will significantly devalue equities over the next 6-12 months.
It sounds like you have information that isn't already priced into the market. That's awesome. You can get rich.
It's being priced in over time. The market doesn't immediately price in future events. We've only rolled back the last 2-4 months of gains so far.
I've already reacted accordingly. There's a lucky Boglehead or stonks investor who was happy to catch the falling knife when I sold. I feel sorry for them but what can you do? People want to believe simple market themes and not look at the driving forces. I'll go back to buy and hold in 6-12 months depending on the fed.
I'd sell more but a lot of it was already in dividend paying stocks like Kraft Heinz which are doing ok and should weather the storm a bit better.
People are increasingly holding their money in stocks even close to when they need it (e.g. retirement) because rates for safer bonds have been mostly below inflation. Of course the market can go down, if you get really unlucky, it can take a few decades to recover, but that hasn't happened for just short of a hundred years now (as long as since the last major pandemic).
If you invested money in stocks that you need in the short term, you are beginning to learn why you don't do that.