The Test Bench › gate

Does Percent of Stocks Above the 20-Day Average actually work?

DEAD

No edge left once tested on a fair footing.

The claim

Percent of Stocks Above the 20-Day Average 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: -0.03 dSharpe (vs buy-hold), OOS

OOS edge -0.03 vs buy-hold; data-mining noise floor ~+0.40 (below it = noise)

Verdict

The short-term cousin of the percent-above-MA family. OOS -0.03 -- the worst of the lot, actively negative. Fast breadth is mostly fast noise.

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.

← Net Liquidity (Fed B/S − RRP) All findings Percent of Stocks Above the 200-Day Average →

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.