S&P 500's 4.4% slide was its worst since April 2025. History says bounces follow

Thursday was ugly on Wall Street. The S&P 500 fell 4.4% in a single session, its steepest one-day decline since April 2025, according to the Kobeissi Letter. That's the kind of red number that sends traders scrambling for the exit.

But the account dug into the history books, and the history books are friendlier than the tape. Before Thursday, the index had notched 56 one-day drops of at least 4.0% going back to 1952. Each of those was a punch in the gut in the moment — and each was followed by a rebound more often than not.

The numbers on the other side of those drops are the interesting part. One week later, the S&P 500 has averaged a gain of 1.0%. The baseline for any random week? Just 0.2%. So the bounce isn't imagination; it's a five-fold edge.

Stretch the window and the gap widens. A month out, the index has averaged 2.0%, versus 0.8% across all periods. Three months out, it has averaged 6.7% — more than triple the typical 2.2%.

The Kobeissi Letter's takeaway is blunt: history suggests the market is set for a meaningful rebound. That's a read on the past, not a promise about the future, and past averages are just that — averages built from plenty of individual outcomes that went the other way.

What matters now is whether this drop behaves like the other 56. Investors will get their first real check within a week, when the one-week average either holds up or doesn't.