numeraire_dataset.load_pastor_stambaugh_historical_beta_portfolios

numeraire_dataset.load_pastor_stambaugh_historical_beta_portfolios(*, start_date: str | None = None, end_date: str | None = None, url: str = 'https://faculty.chicagobooth.edu/-/media/faculty/lubos-pastor/data/liq_vw_hist_deciles_1968_2025.txt', timeout: float = 30.0) → DataFrame

Official historical-liquidity-beta decile returns and traded 10-minus-1 factor.

Columns decile_1 through decile_10 are value-weighted monthly total returns in decimal units; subtract the same-month Fama–French risk_free rate before passing them as equation-14 test-asset excess returns. traded_liq is the author’s supplied decimal 10-1 return (RF cancels) and is retained rather than recomputed. The source has no date field, so the strict parser constructs month-end timestamps from its declared range, requires exactly one row per declared month, and validates 10-1 = decile_10 - decile_1 within eighth-decimal rounding. Inclusive slicing is applied only after the complete source envelope has passed validation.

These are the author’s historical-beta portfolios, beginning in 1968. They are not the predicted-beta portfolios used for the paper’s Table 6 and must not be presented as a Table 6 reproduction. The revision-prone latest snapshot carries the same URL/HTTP/SHA/recipe/slice provenance contract as load_pastor_stambaugh_liquidity(); no raw bytes are persisted.