S&P 400 MidCap Downtrend Replay (1987-08-26 to 1987-10-20)
Replay the 1987 S&P 400 MidCap slide, where the index fell 23.3% from 89.25 to 68.44. Step through daily decision points in this historical scenario, receive AI coach feedback, and sharpen your risk recognition using simulated capital only.
78 daily bars · 11 decision points · 1987-07 to 1987-11 · Stocks
Key facts
This window spans 110 days with a peak-to-trough drawdown of 32.8% and a 10.6% run-up.
- Max drawdown
- −32.8%
- Max run-up
- +10.6%
- Duration
- 110 days
- Largest single-day move
- −13.4%
- Bars
- 78 Daily bars
- Decision points
- 11
Every figure above is computed programmatically from this replay’s own candle series — no editorial input, no LLM. Methodology: Methodology
The market advances day by day. You only see candles up to the current day — as if you were really there.
At key decision points choose Buy / Trim / Exit / Hold. Each decision advances the timeline by one day.
After settlement you get a six-dimension score and an AI coach review. Your result enters the scenario leaderboard.
Event Replay
What happened — and what it teaches
The summer of 1987 set the stage for a quiet but consequential unwind in U.S. mid-cap equities. By late July the S&P 400 MidCap index was trading near 89.25, with sentiment still riding the momentum of the prior year's rally. Volatility was low, positioning was crowded, and the typical mid-cap investor was focused on earnings momentum rather than downside risk. This seven-week window, running from late August through mid-October, would compress a generational drawdown into just over a month of trading days, exposing how quickly mid-cap segments can lead the broader market when the mood shifts.
What followed was a brutal, accelerating slide. The index fell from 89.25 to 68.44, a peak-to-trough decline of 23.3%, with a maximum drawdown reaching 32.8% intra-period. The decline was not a slow leak; a single session captured a 13.4% move, one of the largest single-bar dislocations of the era. Across 78 daily bars, trend, momentum, and volatility all aligned against long-only positioning. Eleven decision points are flagged along the way, four of them marked critical, marking the moments where portfolio actions had the highest potential to either compound losses or preserve capital. These are not hypothetical inflection points; they are the structural pivots of an authentic 1987 tape.
For decision training, the value lies less in the final percentage and more in the rhythm of the move. Coaches using this replay can stress-test how a trainee responds to early distribution days, to capitulation-volume sessions, and to the temptation to bottom-fish a falling index. It illustrates how risk recognition, position sizing, and the discipline to step aside matter far more than directional calls. Most importantly, it trains the psychological muscle of acting on a process when headlines, drawdown, and fear all argue for impulsive decisions, the exact conditions that defined mid-cap investors in the autumn of 1987.
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