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MarketsEvent 2020.02.27 — 2020.05.27

The S&P 500 crossed its 200-day average repeatedly in 2020

A 200-session simple moving average calculated from FRED closing levels shows early reversals of the signal and the later crossing during the recovery.

Updated Nov 8, 2026

When the signal flips during a selloff, which execution assumptions matter?
Verified facts

Recalculating the 200-day average from closes

The calculation averages the latest 200 available closing levels, including the current session. On 2020-02-27 the close of 2,978.76 was below its 3,046.58 average. The index closed above the line on 2020-03-02 and 2020-03-04, and below on 2020-03-03 and 2020-03-05. It closed at 2,237.40 on 2020-03-23 and at 3,036.13 on 2020-05-27, above that day’s 3,000.58 average.

Sources [1]
Interpretation

Signal time and execution time

A rule that acts on every crossover could rebalance several times early in the selloff. Evaluate a closing signal at the next executable price and account for turnover and costs when comparing with holding.

Sources [1]
Limitations

A comparison within one selected period

This calculation describes one selected period in a price index. Dividends, actual trading costs and performance in other periods or markets require separate checks.

Sources [1]

Sources

  1. FRED | S&P 500 daily closing levelsAccessed Nov 8, 2026

Related learning notes

An investment diary for subscribers: Let’s fight back together this November (month 11) | Chesley Investment Advisory Executive Director Park Se-ik [Chesley Official Membership (Internship) / 26.11.07 Sat., early morning]A moving average is a reference for comparing prices, and an index can cross it repeatedly during a selloff. The 2020 US index record helps test the video’s recovery hypothesis by separating signal timing, the next execution price and trading costs.Reading the 200-Day Average and Resistance in a US Stock ReboundUse consecutive S&P 500 closes around the 200-day average in 2020 to compare a one-day recovery with whether support holds afterward. Keep that historical price path separate from the video’s current scenario.Reading the Anthropic IPO Reports and the US Stock ReboundUse actual S&P 500 closes around the 200-day average in 2020 to see when a daily rebound can change a rule-based trend signal. The case is separate from the CTA selling estimate discussed in the video.“A break below the 200-day moving average brings panic selling” | One rule for individual investors in a falling marketThis case computes the note’s 200-day rule on actual US index closes. The same series shows a prolonged period below the line and repeated changes of signal during the initial selloff.