Does yesterday's high or low matter?
It is sold as one of the two or three levels that matter on any chart. We found 68,688 occasions across 19 markets where price traded through yesterday's high or low, and asked whether the day then closed beyond it. Answer: 50.4% — against 51% for a level with no story attached.
The claim
Yesterday's high and low are meant to be decision points: break above and the day belongs to the buyers, break below and it belongs to the sellers. The competing story — the one that has taken over in the last few years — says the opposite: those levels exist to be swept, so a break through them is where the move ends rather than where it begins. Both stories cannot be right, and both are told with charts rather than counts.
What we measured it against
For every day we take the first moment price trades through yesterday's high or low, and record whether the day closed beyond it. Then we do exactly the same thing for a synthetic level the same distance from the same day's open — a level with the same geometry and no history. If yesterday's extreme is special, breaking it should behave differently from breaking a line drawn at the same distance for no reason.
The result
Pooled across 19 markets: 50.4% of breaks through yesterday's extreme closed beyond it, against 51% for the matched level. That is 0.6 points in the direction the sweep story predicts — the famous level is very slightly less likely to hold than an arbitrary one. No spread survives 0.6 points.
| Market | Breaks | Closed beyond | Matched level | Δ | Median distance from open |
|---|---|---|---|---|---|
| EUR/USD | 5,538 | 51.2% | 51.5% | -0.3 | 0.181% |
| GBP/USD | 4,902 | 50.8% | 52.0% | -1.2 | 0.193% |
| USD/CHF | 3,037 | 48.2% | 48.7% | -0.5 | 0.179% |
| USD/JPY | 4,124 | 50.5% | 52.1% | -1.6 | 0.184% |
| AUD/USD | 5,325 | 50.2% | 51.6% | -1.4 | 0.242% |
| USD/CAD | 5,631 | 49.3% | 50.2% | -0.9 | 0.175% |
| NZD/USD | 4,799 | 51.4% | 53.0% | -1.6 | 0.268% |
| EUR/JPY | 4,779 | 51.8% | 51.5% | +0.3 | 0.208% |
| GBP/JPY | 3,811 | 50.4% | 50.8% | -0.4 | 0.228% |
| EUR/GBP | 2,297 | 48.0% | 49.0% | -1.0 | 0.158% |
| Gold (XAU/USD) | 5,418 | 50.6% | 51.0% | -0.4 | 0.361% |
| Silver (XAG/USD) | 4,796 | 39.0% | 41.6% | -2.6 | 0.895% |
| US30 (Dow) | 2,613 | 50.0% | 50.4% | -0.4 | 0.256% |
| NAS100 | 1,645 | 52.9% | 51.0% | +1.9 | 0.399% |
| SPX500 | 1,658 | 51.9% | 51.0% | +0.9 | 0.308% |
| GER40 (DAX) | 2,366 | 50.6% | 51.8% | -1.2 | 0.315% |
| UK100 (FTSE) | 897 | 45.4% | 48.1% | -2.7 | 0.287% |
| BTC/USD | 2,603 | 48.9% | 51.0% | -2.1 | 0.986% |
| ETH/USD | 2,449 | 49.6% | 49.5% | +0.1 | 1.335% |
15 of 19 markets agree — and that is weaker than it looks
15 of the 19 markets lean the same way. That reads like 15 independent confirmations and it is not: these markets move together. We measure US30 and SPX500 at 0.94 correlation of hourly returns, NAS100 and SPX500 at 0.93, BTC and ETH at 0.84. Several of the "agreements" in that table are the same observation counted more than once, which is why we lead with the size of the effect rather than with the head-count.
What we would actually say
- Yesterday's high and low are real levels people watch. That is not in dispute, and it is not the same as a level that predicts.
- The measurable edge is under a point, and it points at the sweep story rather than the breakout story — by a margin far too small to trade.
- Counting markets is not counting evidence when the markets are correlated.
Full method and the raw counts are in section 6 of the evidence page.
Other reports this category sells, tested
Every claim we have tested, including the ones that held, is on the reports index.
We publish the tests that failed as loudly as the ones that held. Every number on this site carries its sample size, and every claim carries what it was measured against.
Read the whole evidence page →