If you build features for Numerai Signals from fundamentals, the single most common way to silently overstate your live performance is joining on the wrong date. Most fundamentals vendors ship data keyed by fiscal period end or a generic "report date" that gets overwritten on every revision. Ne...
Source: [Dev.to](https://dev.to/tradevodata/point-in-time-fundamentals-for-numerai-signals-killing-lookahead-in-your-feature-join-1h54)