ES 15-Minute Standard Deviation: Prediction vs What Actually Happened, September 23 2026 6:30 PM ET
Standard deviation measures how widely price has been scattered around its own average. At 6:30 PM ET on Wednesday, September 23, LiveCharts.AI predicted where Standard Deviation would go over the next 29 15-minute bars of E-mini S&P 500. The second chart shows the Standard Deviation values the market actually produced over the same window. Both panels share one scale, so the shapes can be compared directly.
| Per-bar direction agreement | 20/29 bars — 69.0% |
| Same side of the starting value | 20/29 bars — 69.0% |
| Bars predicted | 29 × 15-minute |
| Standard Deviation at prediction time | 2.56 |
| Where it actually ended | 5.40 |
| Where the prediction ended | 5.17 |
| Size of the move | predicted 2.61 vs actual 2.84 (0.92×) |
| How closely the shapes match | 0.53 (1.00 = identical) |
How this page is selected
Four measurements on the Standard Deviation line have to agree for a window to be shown. Per-bar direction asks, for each interval, whether the prediction and the actual reading moved the same way — here 69.0%. Same side asks whether both stayed on the same side of the starting value — here 69.0%. Size compares how far each travelled — here 0.92×. Shape measures how closely the two lines follow each other overall — here 0.53, where 1.00 would be identical. All four have to pass; agreeing on direction while badly missing the size or the shape is not a match.
What it does and does not say
This is one recorded window, selected because the paths agreed. It is not a typical result, not an average, and not a claim about future accuracy. The prediction shown here had fully matured before this page was written, and was compared against recorded market data after the fact. Live predictions are part of the LiveCharts.AI platform and are not published here.