S&P 400 MidCap Downtrend Replay (1987-03-26 to 1987-05-20)
Replay the 1987 S&P 400 MidCap correction across 78 daily bars with a 9.5% drawdown and sharp 2.7% single-day swings. You step through each trading day, make decisions at 11 key checkpoints, and receive an AI coach review of your reasoning in a simulated, educational environment.
78 daily bars · 11 decision points · 1987-02 to 1987-06 · Stocks
Key facts
This window spans 111 days with a peak-to-trough drawdown of 9.5% and a 7.6% run-up.
- Max drawdown
- −9.5%
- Max run-up
- +7.6%
- Duration
- 111 days
- Largest single-day move
- −2.7%
- 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
Between late February and mid-June 1987, the S&P 400 MidCap index drifted through a corrective phase that tested the discipline of every investor watching mid-cap names. After closing the first day of the dataset near 87.2, the index barely advanced to 88.56 by the final bar — a modest 1.6% net change over 78 trading days. Beneath that sleepy headline, however, the index carved out a 9.5% drawdown from peak to trough and endured a single-day swing of 2.7%, the kind of volatility that punishes both hesitation and overreaction. Eleven decision points, four of them flagged as critical, frame the daily path and turn a flat-to-down tape into a study in patience, sizing, and the willingness to act on plans rather than mood.
What actually unfolded was a slow grind rather than a crash. The index opened the window at 87.2 and closed it at 88.56, so anyone anchoring on the start and end prices would see almost nothing. The drawdown of 9.5% and the 2.7% largest single-bar move tell the real story: mid-caps spent weeks compressing, then snapped with sharp up and down days that rewarded those who had pre-set exits and punished those who sized as if volatility had already normalized. Because the net move was only 1.6%, timing mattered enormously — buying too early into the drawdown eroded returns, while selling too early forfeited the recovery that ultimately lifted the index back to its starting neighborhood.
The training value lies in separating process from outcome. A learner who reads the closing prices alone might conclude nothing happened, yet the path carried a 9.5% drawdown and 2.7% daily jolts across 78 bars. Practicing here means committing to a rule for each of the 11 checkpoints, especially the four critical ones, and letting the review surface where conviction flagged under pressure. The lessons are about pre-commitment, position sizing for realized volatility, and the psychology of holding through a drawdown when the end-to-end print looks benign — exactly the habits a simulated replay can build without real capital at risk.
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