> research · 3 studies

Market ideas, tested on real data.

Out of sample, costs included, sources linked. We publish the answer either way — most ideas that sound clever don’t survive the test, and knowing which ones is worth money.

latest · Sep 23, 2026 · backtest

Can you trade coffee on the weather?

−10.6%No edge

weather model, 20 months out of sample

Arabica moves on weather forecasts, days before the thermometer confirms anything — and the stocks that buy the beans feel it a year later, through margins.

stocks in itSBUX SJM KDP MCD KO XLP

Read the study Check your concentration

Area chart of ICE arabica coffee futures for December 2026 delivery from January 2 to September 22, 2026: from 323 cents a pound in January down to a 234-cent low on June 9, a 27% jump to 335 cents on July 6 while the coldest night in the Minas Gerais coffee belt was 7.6°C, a 342-cent high on August 24 and a close of 272 cents on September 22

data · ERA5 weather · ICE arabica · 2016–2026

Earlier studies

question · answer · evidence

Sep 20, 2026
field study

Where do brokers hide the list of what you own?

Portfolio, Positions, Holdings and three more. Seven brokers don’t open on your holdings at all, and one buries them three menus down.

data · 17 brokers, menu paths recorded · Sept. 2026 · import from your broker →

6 namesfor one screen, across 17 brokersNo convention

Sep 19, 2026
event replay

Does gold protect a portfolio in an oil shock?

Gold rose 7% in the two weeks after the 2022 invasion, then rate hikes took it below where it started. A long-run diversifier, not a two-week hedge.

stocks in itGLD XLE SPY

data · Brent, COMEX gold, STOXX 600 · 2019–2026 · replay shocks on your portfolio →

−14.6%gold vs its pre-war price, Nov. 3, 2022Not for long

House rules

01
Out of sample
A rule is judged on data it never saw. In-sample wins are where most backtests go to lie.
02
Costs counted
Every trade pays for itself. An edge that vanishes after fees was never an edge.
03
Failures published
A clean “no” is a result. It saves you the money of finding out yourself.
04
Sources linked
Every figure traces to its source, and the code behind each backtest is kept with it.

The same tests, on what you own

Replay past crashes on your holdings, see how concentrated you really are, and track every position in one place.

Crash test X-ray Import your portfolio

Research, not recommendations. Not investment advice.