Cycle Forecast

Forecasts › S&P 500 › Sep 18, 2026

S&P 500 cycle forecast of September 18, 2026

1 of 3 published turn dates landed within two sessions of a real turn of the same kind. Moved to random positions, the same dates would have scored 1.5 on average.

walk-forward test Walk-forward test: it was made on November 14, 2026 by running the same engine with prices only up to September 18, 2026. Nothing after that date was visible to it. Window: Sep 19 – Oct 16, 2026.

730740750760770780Jul 1Jul 15Aug 1Aug 15Sep 1Sep 15Oct 1Oct 15Price · daily close (SPY, $)Cycle lineforecast from Sep 18Sep 29top ✗Oct 7bottom ✓Oct 14top ✗
755760765770775780Aug 15Sep 1Sep 15Oct 1Oct 15Price · daily close (SPY, $)Cycle lineforecast from Sep 18Sep 29top ✗Oct 7bottom ✓Oct 14top ✗
Price before the forecastPrice after itCycle line, forecastCycle line, fitted on past pricesPublished turn dateReal turn of the price

Turn by turn

DateTurnWhat the cycle line doesWhat the price did
Tue, Sep 29Topstops rising and turns down✗ miss – the price made a bottom there (Sep 30)
Wed, Oct 7Bottomstops falling and turns up✓ hit – real bottom on Oct 8, 1 session later
Wed, Oct 14Topstops rising and turns down✗ miss – the price made a bottom there (Oct 16)

Direction over the four weeks

The cycle line ended the window higher than it started; the price moved +0.2% (761.64 → 763.27). ✓ Same direction.

Current S&P 500 forecast →   Track record →