The claim

A common session model says Asia builds a range, London sweeps one side of it, and New York then runs the other way. Traders treat the London sweep of Asia as the setup that starts the day.

How we tested it

We measured 9,168 market-days over five years on Nasdaq 100 (NQ), S&P 500 and gold CFD prices and on Bitcoin, Ether and Solana, with sessions on New York time adjusted for daylight saving: Asia 18:00–01:00, London 01:00–08:00, New York 08:00–15:00. Every result was repeated with the day starting at 17:00 instead of 18:00. We compared the full sequence with what its parts would produce if they were independent, then tested it as a live forecast at the New York open, matched on distance to the target level. A separate count on 1,284 days of CME NQ futures (2021–2026) cross-checks the base rate.

What we found

London traded through Asia's high or low on 92.8% of NQ days, 93.6% on the S&P 500 and 91.0% on gold; on the three crypto markets it was 76.3–79.6%. On CME NQ futures the figure was 92.5%, and New York went on to trade through London's high or low on 99.1% of days. When Asia's range was in its quietest third, London took an Asia extreme on 98.4% of NQ days: a narrow range is simply easy to trade through.

The full sequence happened about as often as its parts would by chance. On NQ, after a quiet Asia and a London sweep, New York closed beyond London's opposite extreme on 36.4% of days, against 33.2% on all days (p = 0.19). Gold (p = 0.11) and the S&P 500 (p = 0.25) were not significant either.

As a live forecast it failed. Using only what was visible at the New York open, the sequence appeared to raise the chance of New York reaching the previous day's high or low that yesterday's close pointed towards by 9.4 points. Matched on how far price already was from that level, the difference became −2.5 points (z = −1.78), negative or null on all six markets. Out of sample, distance alone (AUC 0.762) predicted the outcome better than the daily lean plus the full session profile (AUC 0.680).

What to do with it

Treat a London sweep of Asia as the normal state of the day rather than a trigger. If you use session levels, how far price is from the next level carried more information in this test than the session story did.

Limits

The main study used CFD prices for NQ, the S&P 500 and gold; the CME futures check covers the base rates only. It measured whether levels were reached, not the result of any trade.

Education only, not financial advice. These are measurements of past data, not a forecast or a signal.