The other point I'll make is this shows the futility of the "20% rule" - where you sell after the market has dropped 20% from its high, and buy after its up 20% from the bottom. The reasoning is superficially plausible - you cash out before there's a big market plunge, and you buy back in after there's some sustained gains (so you don't buy in and see the market dip more). So, it sounds plausible - the problem is it doesn't work in practice.
The theory's been around for decades, and the percentage keeps changing (I've heard 5% or 10% instead of 20%). And the theory had some newfound popularity about a decade ago, as this strategy would have worked very well during the Great Recession. But it would have caused you to lose money during most other times of market volatility over the past 40 years.
In this case - the S&P set an all-time high on February 19th, at 3,386. A 20% drop from that is 2,708, which it reached on March 16th. So you'd sell (in the middle of a once-a-decade panic) at the close of 2,386. The market sets a new low a few days later (2,237 on March 23rd). The market is up 20% from that low on April 8th, when it closes at 2,749.
The end result is - you'd sell in a panic at 2,386 and buy back a few weeks late at 2,749. You've sat out for three weeks, and you've bought back in at prices that are 15% higher than when you sold. Not so good.
Someone might say I'm being unfair, since I'm assuming you sold on March 16th at the daily close (of 2,386), as opposed to immediately selling when it hits 2,708 (20% off the previous high). The problem is the index plummeted after hours, and only opened at 2,508. So even if you sold instantly when the market opened, you'd still have to buy in at prices 9.6% higher than when you sold. Not to mention you'd incur unnecessary commissions on each transaction, and you'd trigger taxes if this is outside a tax-deferred account.
I've studied this approach back to 1980. I can post data for other periods if people are interested. Like I said, this strategy would have served you well during 2008/2009 (which is probably why the theory briefly made a comeback), but it causes you to lose money far more often than it helps you.