At a glance
The short version
Which levels, and why these
Previous day high and low bound yesterday's range, and a market that opens inside it and leaves is telling you something different from one that opens outside and comes back. The daily and weekly opens are reference prices for premium and discount — above the open is expensive, below is cheap, and a surprising amount of intraday method reduces to that one comparison. Premium and discount covers the framing.
Yesterday's high, low and close are also the whole input to a floor-trader pivot. The pivot point calculator turns them into R1–R3 and S1–S3 and shows how often each was actually reached over five years: R1 on roughly 45% of days, R2 on under 20%. Useful context for a PDH or PDL target.
Session opens matter for a different reason: they're where a new pool of participants arrives. A level that held all through Asia often means nothing five minutes after London opens, which is a fact your backtest will surface if you log the session and won't if you don't.
What to actually measure
Reaction rate is the obvious one — how often price touches the level and turns. The more useful one is conditional: how often it turns given that it arrived from below, in the New York session, after a sweep. Unconditional reaction rates on obvious levels hover near coin-flip on most instruments, which is why "the PDH works" and "the PDH doesn't work" are both defensible and neither is useful.
Log the misses. A level that price slices through without pausing is the trade that costs you money, and a backtest that only records touches-and-turns is measuring your memory, not the market.
We measured the first half of that on 13 markets over four years. The previous day's high or low was taken on about 85% of days, the side nearer the open went first roughly four times in five, and once one side went the other followed on only about 13%. The textbook sweep-and-fade at PDH or PDL came out at zero before costs. The free previous day high and low statistics tool has every market, and it is the baseline your own conditions have to beat.
Frequently asked questions
Which levels does it draw?
Previous day's high and low, the daily open, the weekly open and the session opens — drawn automatically for every day of the replay, at the values they held at the time.
Are the levels correct in my timezone?
The levels are anchored to the market's own session clock rather than to your browser's, which is what makes a New York open the New York open regardless of where you're sitting. The session times tool shows the windows in your local time.
Can I run these with other concepts?
Yes — key levels plus liquidity sweeps is the most common pairing, because it shows both the level and the moment it gets taken.