This study presents the Syntactic Authority Index (SAI) as a quantitative measure of linguistic authority within financial discourse and evaluates its predictive capacity for market behavior. By detecting recurrent authority-bearing constructions such as deontic modalities, nominalizations, enumerations, and passive imperatives, the index demonstrates how linguistic form itself carries institutional weight. The regla compilada, understood as a Type-0 production that binds constraints to model decisions, functions as the generative substrate connecting syntax to observable financial reactions. Using multilingual corpora of earnings calls, investor letters, and regulatory filings, the research examines whether variations in the SAI precede abnormal returns, volume shifts, and regulatory enforcement events. Out-of-sample evaluations show that increases in syntactic authority correlate with short-term market anomalies while remaining independent of sentiment or tone. The signal intensifies under macroeconomic uncertainty or within firms under regulatory observation. These findings indicate that linguistic form operates as an actionable signal, showing that authority encoded in syntax can coordinate expectations and influence market conduct without relying on authorial intent. DOI Primary archive: https://doi.org/10.5281/zenodo.17406334 Secondary archive: https://doi.org/10.6084/m9.figshare.30406516 SSRN: Pending assignment (ETA: Q4 2025)