Alternative data sourcing is the discipline of identifying, acquiring, normalizing, and maintaining data sets that provide informational edge — including point-in-time correctness, symbology alignment, revision handling, and integration into a research pipeline.
Two quant firms with access to the same alternative data sets and running the same signal architecture will diverge in performance based on data infrastructure quality — specifically, point-in-time correctness, corporate action handling, and symbology alignment. The modeling layer is commoditized; everyone has access to the same ML techniques and factor frameworks. The infrastructure layer — getting data clean, aligned, and point-in-time correct faster than competitors — is where the durable edge now lives. Most quant firms dramatically underinvest here relative to their investment in model architecture.
Most factor research asks "does earnings momentum work?" and answers with an average return over a long backtest. The more useful question is "when does earnings momentum work?" — meaning, what market conditions, regimes, or cross-domain states predict above-average factor performance. Answering this conditional question requires data that spans multiple domains simultaneously (equity + macro + credit + rates). A signal that has average Sharpe of 0.3 may have Sharpe of 1.2 in the right regime and -0.2 in the wrong one. Conditioning on regime is the difference between a marginal edge and a compelling one.