Black Monday: The Bounce

October 20, 1987: +5.33%. The S&P closed at 236.83, up from 224.84. The day after the worst crash in history, the market rallied. Not a modest relief bounce — a full-throated, 5.33% surge that was, at the time, one of the largest single-day gains ever recorded. But calling this day a "rally" understates the chaos. The market opened lower, then whipsawed violently as traders tried to figure out if the financial system was intact.

Alan Greenspan, who had been Fed chairman for barely two months, issued a one-sentence statement before the opening bell: "The Federal Reserve, consistent with its responsibilities as the nation's central bank, affirmed today its readiness to serve as a source of liquidity to support the economic and financial system." That single sentence — the original Fed put — was the most important thirty-one words in financial history. It told the market that the central bank would not let the crash become a systemic failure.

Of 756 stocks in the database that day, only 168 advanced while 533 declined. The average stock fell 5.58%. The index rallied because the largest companies — the ones that had been hit hardest on Monday — bounced the most. Procter & Gamble surged 22.45%. Honeywell jumped 31.15%. Coca-Cola gained 19.67%. AT&T rose 20.13%. Exxon added 18.22%. The blue chips led the recovery while hundreds of smaller stocks were still falling or couldn't trade at all.

The names on this list are a roll call of American capitalism. These were not speculative stocks or penny shares — they were among the largest, most liquid companies in the world. Their 20%+ gains on a single day reflect how catastrophically they had been mispriced on Monday, and how quickly the market corrected once Greenspan signaled that the Fed would backstop the system.

October 21, 1987: +9.10%. The S&P closed at 258.38, up from 236.83. This was the real bounce. On Tuesday, October 21, the rally broadened beyond the blue chips. Of 757 stocks, 601 advanced (79.4%), only 79 declined, and 77 were flat. The average stock gained 7.77% and the median return was 6.60%. This was not a narrow, defensive rally — it was the entire market roaring back.

The +9.10% gain was the largest single-day rally since 1939, and it came just two trading days after the largest crash in history. The proximity is not a coincidence. The violence of the crash created the conditions for the violence of the recovery. Stocks that had been dumped indiscriminately on Monday — many of them falling not because anything was wrong with the underlying business but because sellers had no buyers — were suddenly cheap enough to attract value investors, corporate buyback programs, and bottom-fishers who sensed that the panic had gone too far.

The two-day cumulative gain from Monday's close was 14.92%. If you had bought the S&P 500 at the close on Black Monday and held for 48 hours, you would have earned nearly 15% — in two days. But to capture that return, you had to buy at the most terrifying moment in market history, when every headline screamed that the financial system was collapsing.

The recovery from Black Monday was not a straight line up. After the two-day snapback, the market fell again — 3.92% on October 22, then another 8.28% on October 26, retesting the post-crash lows. For a terrifying few days, it looked like the bottom might not hold.

October 29, 1987: +4.93%. The S&P closed at 244.77, up from 233.28. The third rally of October 1987 came ten days after the crash, and it had a different character than the first two. The panic selling of October 26 had brought the index within 3 points of the Black Monday close, but this time the buyers were more organized. Corporate treasurers, who had been authorized by their boards to buy back stock, stepped in. Institutional investors who had been paralyzed during the first week began placing orders. Of 756 stocks, 513 advanced (67.9%) with an average gain of 3.76%. The breadth was solid, if not as overwhelming as the October 21 rally.

After October 29, the market stabilized. There were no more +4% days in 1987. The S&P ended the year at 247.08 — still down 23.6% from the August high of 329.80, but well above the Black Monday low of 224.84. The crash that many feared would trigger a recession turned out to be a market event with minimal impact on the real economy. GDP grew every quarter in 1988. Unemployment continued to fall. The lesson was clear: the market can detach from the economy, at least temporarily, and the corrections can be as irrational as the crashes.

Perhaps the most remarkable fact about 1987 is that the S&P 500 ended the year higher than it started. The index opened January at 242.17 and closed December at 247.08 — a gain of 2%, despite containing the worst single-day crash in market history. An investor who went on vacation in January and returned in December would have seen a modest positive year and missed the entire drama. The crash happened entirely within a year that, in aggregate, was positive.

This is one of the most powerful illustrations of why timing the market is so difficult. Selling after Black Monday — the "obvious" response — would have locked in losses at the exact moment the recovery was about to begin. Buying on the crash day would have produced a 10% gain by year-end. But nobody knew that on October 19. On that day, the only certainty was fear.

The stock-level data reveals something important about how crashes and recoveries work. On October 20, the day after the crash, the S&P 500 index rallied 5.33% — but only 22% of individual stocks advanced. The average stock fell 5.58%. The rally was driven entirely by mega-caps bouncing from oversold extremes. Many smaller stocks couldn't trade at all — market makers had withdrawn, and there were simply no bids.

By October 21, the recovery had broadened: 79% of stocks advanced, and the average gain was 7.77%. By October 29, the third rally, 68% of stocks advanced with an average gain of 3.76%. Each successive rally was broader but less intense — the initial snap was concentrated in the largest stocks, and the recovery gradually filtered down to the rest of the market.

This pattern — narrow recovery first, then broadening — would repeat in 2008, 2020, and 2025. It is the signature of how markets heal: the most liquid names recover first because they are the easiest to buy, and the rest follow as confidence returns.