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Fifty-six trading hypotheses: what systematic signal research actually looks like

Quant, Research, Backtesting, Python

New to some of the terms? See the glossary at the end.

For about a year, from 2025 into 2026, I hunted for trading signals. Not by tinkering until a chart looked good, but with rules: every idea was written down and registered before I tested it, run through the same five tests, and either killed or kept. I looked at currencies, gold, US stocks and ETFs, crypto, volatility, pairs of similar stocks, calendar effects, and how markets behave around US Federal Reserve meetings.

By the time I first wrote this up, I’d tested 33 ideas and the note was titled, honestly, “Thirty-three failures”. Nothing had survived. By 56 ideas, something more interesting had happened. Four ideas passed every test I’d set, and then fell apart, or failed to confirm, on data they had never seen.

This post is about that gap between “it passed the backtest” and “it’s real”, and about a second mistake I only caught by going back over my own old verdicts.

Update, October 2026. This post covers the first 56 hypotheses. The registry has since grown to 157. Two changes matter. The one “inconclusive” survivor below (turn of the month) was later downgraded. And a group of equity regime-timing signals, such as credit spreads and yield-curve inversion, passed the gauntlet and then held up on the unseen 2023–2026 data, the first gauntlet passes to do so. But that window was a strong bull market: simply holding SPY and QQQ scored a Sharpe ratio of 1.38 over it, and the three timers I can line up against that scored 0.77, 1.29 and 1.36. They survived; none has yet been tested through a bear market or shown to beat buy-and-hold.

The five tests

I called them the gauntlet. I fixed them before testing anything, and I never loosened them when an idea came close:

  1. Walk-forward testing. Tune on one stretch of history, test on the next, roll forward, repeat. To pass, a strategy needed a Sharpe ratio of at least 0.50 after costs on the periods it wasn’t tuned on.
  2. Cost stress. Double and triple the trading costs. If the edge halves, it was never really there: it was inside my margin of error on costs.
  3. Parameter wobble. Nudge every setting by 25% either way. A good idea degrades gently. One that falls off a cliff only worked by accident at one exact setting.
  4. Different markets. The signal had to show some skill in at least two of four conditions: rising, falling, volatile and sideways. An idea that only works in one kind of market is a bet on that market coming back.
  5. A penalty for trying too much. Test enough versions of an idea and one will look great by pure chance. The deflated Sharpe ratio raises the bar for every related version you’ve already tried.

The lockbox

There was one more safeguard. I locked away all data from January 2023 onward and never looked at it while designing or testing anything. The deal I made with myself: an idea that passed all five tests would get to open the lockbox exactly once. A blind final exam, not another practice round.

Four ideas earned it. Here’s how they did:

Hypothesis Gauntlet Sharpe (2007–22) Lockbox Sharpe (2023–26)
Cross-asset momentum/reversal (BTC, SPY, GLD, TLT) +0.51 −0.50
Pairs trading, 7 same-industry stock pairs +0.67 −1.10
Pre-FOMC announcement drift (SPY, QQQ) +0.52 −0.17
Turn-of-month seasonality (SPY, QQQ) +0.53 +0.04

Gauntlet versus lockbox Sharpe ratios for the four hypotheses that passed every test

Three clear failures, and one result too close to zero to mean anything. I’d built this whole process specifically to stop me fooling myself, and it was wrong in all three cases where the answer was clear.

That doesn’t make the five tests useless. They threw out 52 of the 56 ideas before those ever got near the lockbox. But it taught me that “passed my tests” and “found something I could trade” are two different claims.

Why the winners lost

What made these failures useful is that none of them was bad luck. Each had a reason I could point to.

The cross-asset strategy learned from an unusually generous period. Its training years included the COVID crash, the sharp recovery and the 2022 interest-rate shock: perfect conditions for “buy what fell, and add some uncorrelated momentum”. The calm bull market of 2023–2025 had nothing like that. Digging into it turned up something worse. The strategy looked back 63 days at Bitcoin, which only catches the tail end of a crash, so it would bet against Bitcoin right as a multi-year bottom was forming. That’s not noise; it would happen again at every crypto cycle low.

I wrote and pre-registered a fix: a one-year lookback, closer to Bitcoin’s roughly four-year cycle. When I finally ran it, it was the best result that family of ideas ever produced (a Sharpe ratio of 0.70). It still failed, because by then I’d tried enough related versions that the penalty bar had risen to 0.73. So a sensible fix for a real problem will never get its lockbox exam. A frustrating place for an idea to end.

Choosing in advance doesn’t protect you from a changing world. I picked the seven stock pairs before testing, so this wasn’t cherry-picking. But three of them, Walmart/Target, UPS/FedEx and Caterpillar/Deere, turned out to be businesses drifting apart for good, not prices wobbling around a stable gap. A redesign with a stop-loss and a maximum holding time improved those three by 6–28 percentage points each, exactly as planned, and the portfolio still lost money (Sharpe −0.86). A new loser turned up in a pair nobody had worried about.

Knowing an effect is fading doesn’t tell you where it’ll land. This is the one I did almost everything right on. US stocks tend to rise the day before Fed announcements, a well-known finding (Lucca and Moench, 2015), and the research already said the effect had weakened after 2016. I compiled the Fed’s meeting dates by hand, one year at a time, set up a test to check the fade, and my data reproduced it almost exactly: a Sharpe ratio of 0.85 in 2011–2015 against 0.10 in 2016–2022. Then the lockbox came back at −0.17, below even the weak version I’d predicted. Understanding why something is weakening explained the shape of the failure. It didn’t stop it.

My verdicts were going stale

This was the mistake I didn’t see coming, and I only found it by going back and re-running ideas I’d already decided on.

Remember the penalty for trying too much? My system counted related attempts live, from the registry. So the very first idea in a new family paid no penalty at all. When I later added related ideas, the bar went up for every new one, but nothing ever went back and re-checked the first.

Two of my four “passes” were first in their families. I re-ran both with exactly the same rules and the same 2007–2022 data, and got the same results as before. But against the bar their families had grown into, both failed badly. The cross-asset strategy’s score fell from about 1.0 to 0.017; the pairs strategy’s to 0.386. Both needed 0.90.

In other words, two of my four “it passed!” moments wouldn’t happen if I proposed the same idea today. The market hadn’t changed. Only the size of my own search had. A “robust” label was only true until I tried a sibling. The fix is simple: re-check a family every time it grows. I just hadn’t been doing it.

The two safeguards catch different things. The penalty corrects for how many ideas I tried. The lockbox corrects for the world changing, which no amount of statistics on old data can see coming.

How the other 52 died

The ideas that never passed the five tests failed in three ways, and each one taught me something different:

  • Backwards. Buying US index funds that had been rising turned out to lose money in every kind of market, which is how I discovered that at that time scale, betting on a reversal was the better idea. Currency breakouts tended to fizzle out rather than keep going.
  • Right idea, wrong playing field. Betting on short-term bounce-backs across 54 stocks did predict something real, but trading it daily cost more than it earned. Currency carry is a real, well-documented return, but five currency pairs are too few to survive its occasional crashes.
  • Right idea, wrong timescale. Gold really does move against real interest rates, over years. Over 20 trading days, the same relationship pointed the wrong way.

The lockbox adds a fourth kind that the first three can’t catch by design: a real edge, an honest pass, and the wrong decade.

A real signal I couldn’t trade

The strongest finding in the whole project isn’t a strategy at all. Index funds that had fallen most over the last three months tended to do better over the next three. As a predictor, it was strong (an information coefficient of +0.28 to +0.41, where academic stock signals typically manage 0.05 to 0.10), and it held up in every kind of market.

I never managed to turn it into money. Six different versions produced Sharpe ratios between 0.12 and 0.43. The problem is that US index funds move so closely together that seven of them act like five or six separate bets at most. Adding Bitcoin to spread the risk got one version through the five tests, and then the lockbox caught it anyway. Fixing the problem you can see doesn’t mean there isn’t another one hiding behind it.

What I’d keep

If I started over tomorrow, I’d keep these:

  • Write the rules down first, and don’t move them. That’s the only reason any of these failures mean anything.
  • Keep a lockbox, and open it once. Nothing else told me what it told me.
  • Treat “it passed” as “it’s earned one blind test”, not “it works”. I only use the word deployable after a lockbox pass.
  • Re-check old verdicts as the search grows. Statistical corrections go stale.
  • Always compare against doing nothing clever. The update at the top is why: surviving a bull market while being invested 90% of the time doesn’t prove much yet.
  • Keep the story, the backtest and the blind test as three separate facts. Don’t rewrite one after seeing another.

Good economic reasoning, a clean pass on every test and agreement with published research can all line up, and a strategy can still fail the one exam it can’t game. What I have to show for this year isn’t a money machine. It’s a registry where every dead idea records what I tested, why, what I found, and what happened when it finally met data it had never seen. I think that’s worth more.

Glossary

Backtest
Running a trading rule on historical data to see how it would have performed.
Buy-and-hold benchmark
Simply owning the market the whole time. A timing strategy has to beat this to be worth its complexity.
Carry
Earning the interest-rate difference between two assets, for example holding a high-yielding currency funded by a low-yielding one.
Deflated Sharpe ratio (DSR)
A Sharpe ratio adjusted for how many related ideas were tried. The more variants tested, the higher the bar, because some will look good by chance.
ETF
Exchange-traded fund: a fund that tracks an index and trades like a share, such as SPY for the S&P 500 or TLT for long US Treasuries.
Family
A group of hypotheses built on the same underlying idea. Multiple-testing penalties are counted within each family.
Gauntlet
This lab's five fixed tests every hypothesis had to pass: walk-forward Sharpe, cost stress, parameter perturbation, regime IC and the deflated Sharpe ratio.
Hypothesis
A specific, written-down trading idea, such as 'stocks that fell most last week rise next week', registered with its rules before it is tested.
Information coefficient (IC)
The rank correlation between a signal's prediction and what actually happened next. 0 means no skill; 0.05 to 0.10 is typical for a useful equity signal.
Lockbox (holdout)
Data kept completely untouched during research, here everything from 2023 onward, and opened once as a final blind test.
Market regime
A broad market condition, such as trending up, trending down, highly volatile or moving sideways. A signal that only works in one regime is fragile.
Maximum drawdown (MaxDD)
The largest fall from a peak to a later low in a strategy's value, in percent.
Momentum and reversal
Momentum bets that recent winners keep winning; reversal (mean reversion) bets that recent winners and losers swap places.
Out-of-sample (OOS)
Data the strategy was not designed or tuned on. Results on it are a fairer test than results on the data used to build it.
Pairs trading
Buying one stock and selling a similar one when their usual price relationship stretches, betting it snaps back.
Pre-FOMC drift
The tendency of US stocks to rise in the day before Federal Reserve (FOMC) rate announcements, documented by Lucca and Moench (2015).
Pre-registration
Writing down the test, the data and the pass mark before running anything, so the result cannot quietly change the rules.
Probabilistic Sharpe ratio (PSR)
The probability, from 0 to 1, that a strategy's true Sharpe ratio beats a given benchmark. This lab required at least 0.90.
Sharpe ratio
Return per unit of risk: average return divided by its volatility, annualised. Around 0.5 is respectable for a single strategy; above 1 is strong.
Walk-forward testing
Tuning a strategy on one stretch of history, testing it on the next, then rolling forward and repeating, so every test period is out-of-sample.