Being long and short at the same time means the market's direction cancels out. What is left is whether the winners keep beating the losers - which is a real question, not a bet on the market going up.

Here is what that came from.

After 378 failures, one strategy finally passed the test that killed all the others.

Rank 45 perpetuals by 5-day return. Long the top 5, short the bottom 5, hold 15 days, rebalance. Equal weight, dollar-neutral.

The out-of-sample control is the one that had destroyed everything before it: fix the settings on old data, then run them on data the search never touched. In-sample +1.711% per rebalance, out-of-sample +1.801%. The mean held.

It also survives costs far worse than real: still +0.48% per rebalance even at a 1.50% round trip, six times what Binance actually charges.

Part of a public experiment:...