Quantitative model marketplaces often suffer from publication bias, survivorship bias, and p-hacking—assuming any statistics with p-values are presented in the first place. Much of this can be mitigated by pre-registering studies.
I recently launched two Designer Models and have never opened any others. They should become publicly visible in about 3 months, ensuring no survivorship or publication bias.
My hope is that these models will perform well and that the pre-registration will validate the statistical results. But this should add to the discussion of backtesting decay and the effects of survivorship bias in any case.
Both models are pre-registered here: OSF
Edit: I was thinking about why pre-registration helps. The literature on this is pretty dry, but really, it is just like calling your shot in billiards.
I can be aiming at the 7 ball trying to get it in the side pocket, miss entirely, bank the cue ball off the cushion, hit the 9 ball, and send it into the corner pocket. Then I post that shot online claiming I'm great at billiards. I post if did not call my shot ahead of time, I should say.
The analogy is looking at 156 models, finding the single best performer, and claiming it was pure skill. If you had called that specific model ahead of time, it actually would be impressive—or at least the odds of true skill shoot up dramatically.
Looking at Designer Models should be exploratory at first. You may like the designer, the backtest, or the out-of-sample results—all legitimate. But then you need to call your shot going forward. Write it down, specify some statistics, or set a clean benchmark—something like "I think this will beat 95% of Designer Models 3 years from now."
That is dramatically different than picking whichever ball drops after a break and calling it skill. For most players, it wasn't.
If you want the dry statistical version: unless you set a strict end date for the study in advance, over half of all random studies will show statistical significance at some point. And actually, given enough time, the probability approaches 100%