S&P 500 · May 31, 1988

The first session after the long weekend

+3.45%

single-day change vs previous close

Part of a longer stretch

Back from Black Monday

early in it · 1987-12-04 → 1989-07-26, +50.97% over the whole period

What happened that day?

31 May 1988 — the S&P 500 rose 3.45%. No single cause for that one day could be pinned down
The four sessions before it went almost nowhere. The move arrived all at once
The previous day was a US holiday, so this was the first session back — and also the last trading day of May
The aftershocks of the October 1987 crash were still running. The index had slipped again from mid-April into late May
That slip bottomed in late May, and this was the start of taking it back
From the April high to the May low the index fell 7.64% — shallow, for the year after a crash

Sources

Every figure on this page is recomputed from the original daily closing prices and checked against them at build time. The account of what happened is put together from the public record; where a specific source was consulted it is listed above.