The f*cking harness prompt Anthropic engineers didn't ship you
So I rebuilt it from scratch for Opus 5.5.
You paste it into Claude Code and it stops acting like an intern with root access.
Reads the project rules before it touches a single file.
Every tool call comes back with receipts. No "trust me bro".
Subagents get only the files they need, not your whole repo.
Anything it can't undo waits for your yes. A no stays a no.
3 failed fixes on one bug and it stops and says BLOCKED instead of nuking the codebase.
Same error twice and it writes a rule so it never happens again.
It only calls the job done with a diff and real test output.
Copy it, drop it in, go touch grass while Claude does the boring sh*t.
this quant research note is f*cking brutal
it shows how easy it is to manufacture a “great” strategy just by testing enough ideas
under the null model:
10 strategies → 4.6% chance of finding Sharpe ≥ 2.0
100 strategies → 36.9%
500 strategies → 86.5%
1,000 strategies → 98.2%
that is the whole trap
the more strategies you test
the more likely randomness gives you a winner that looks real
and the paper shows exactly what happens next:
in-sample Sharpe: 2.30
out-of-sample Sharpe: 0.12
so the quant workflow has to be ruthless:
resample the data
control multiple testing
remove common factors
validate out-of-sample
include realistic costs
because a high Sharpe is not proof of edge
sometimes it is just the best-looking accident in a huge search
randomness will always create attractive backtests
the edge is surviving the attempt to prove them fake