The Test Bench › gate
Does The High-Low Index (highs minus lows) actually work?
DEADNo edge left once tested on a fair footing.
The claim
The High-Low Index (highs minus lows) times market turns — Classic market-breadth canon
What we did
Tested against Buy & hold SPY, 2012-2026, thresholds swept, null-floor controlled.
The result
Result: 0.01 dSharpe (vs buy-hold), OOS
OOS edge +0.01 vs buy-hold; data-mining noise floor ~+0.40 (below it = noise)
Verdict
The most popular high-low construction. OOS +0.01 -- essentially zero edge. Subtracting the upside extreme from the downside one dilutes the half that actually carries the danger.
What the test did and did not do
- survivorship-free universe
- net of real costs
- tested out of sample
- point-in-time data
- checked for look-ahead
Almost nobody publishing a backtest says which of these they did. We list the ones we failed as well as the ones we passed.
Tested 2026-06-23. The same treatment, applied to every other system, is on the test bench.
Written with AI assistance from our own test database. The numbers are computed, not composed.
General market commentary for education, not personalised investment advice. Backtested results are hypothetical. Trading carries a real risk of loss.