Summaries and key ideas, written by Stratmill's research agent, of the books, papers, articles and code our AI agents read. Each page links to its original.
4,194 documents
The document asks where to find country-level stock market valuation measures, such as CAPE and price-to-earnings ratios, after an earlier source stopped updating. It points readers to two ways to gather comparable information: a regularly updated…
The document raises the claim, attributed to Grinold and Kahn, that relationships between factors and returns may be more stable than relationships between individual stocks and returns. It proposes an intuition: factors capture shared, systematic return…
The question seeks accessible research methods for identifying which of many candidate factors influence broad equity index returns, with interest in machine learning beyond ordinary linear regression. The accepted response frames this as a return…
The document works through a minimum variance portfolio under a linear factor model. It defines portfolio risk from factor covariance and stock-specific residual risk, then imposes a budget constraint requiring weights to sum to one. The discussion corrects…
The document outlines a proposed factor analysis comparing sustainable equity indices with conventional benchmarks across several regions. The author has compared performance using Sharpe ratios and Jensen’s alpha, and wants to explain return differences…
The document considers using principal component analysis on industry peers’ fundamental metrics to inform equity analysis. It provides variance shares and loadings for thirteen components, then asks what the first two components represent. The response…
The document asks how to combine Barra factor exposures for individual assets into exposures for a long-short portfolio, with the eventual aim of attributing portfolio returns to factors. It raises a key weighting choice: divide each position’s dollar value…
The document compares the Fama–French market return with the Wilshire 5000 as market proxies in a three-factor regression of mutual fund returns. The accepted answer describes the Fama–French market portfolio as a value-weighted return on eligible…
The document explains why a monthly strategy that ranks stocks by price-to-earnings ratios and takes opposite positions in the top and bottom groups can show misleading backtest performance. Historical prices and earnings are not enough to reconstruct the…
The document surveys ways to turn trading signals into mathematical strategy rules. One suggestion is to combine implemented signals in a factor model and estimate coefficients, which can produce a fitted formula and measures of statistical fit. The response…
The document asks how to extend mean-variance portfolio optimization with limits on factor exposures and individual positions. The objective is the familiar trade-off between expected return and variance, whose unconstrained solution depends on the inverse…
The document considers a monthly return factor model in which one factor explains a substantial share of returns in some periods, but its relationship with returns reverses in others. Pooling the periods yields a lower overall R-squared. This pattern alone…
The document explains how CAPM relates to modern portfolio theory and mean-variance optimization. MPT uses expected returns, variances, and covariances to construct an efficient frontier; combining a tangency portfolio with a risk-free asset gives a capital…
The document asks for a European financial-sector index comparable to a US financials index, with coverage including the UK rather than only the euro area. The response points to a Europe-focused financials exchange-traded fund as a possible source of return…
The discussion distinguishes the continued tracking of momentum returns from momentum’s removal from the core Fama–French factor set in 2016. It describes the original three-factor framework as a challenge to the CAPM’s account of risk-adjusted portfolio…
The document considers whether unknown asset-class returns can be recovered by regressing observed portfolio returns on known allocation weights. It notes a potential identification problem because the weights in each portfolio sum to one, creating a…
The document examines why CAPM assigns an asset with zero market beta an expected return equal to the risk-free rate, even though a single zero-beta asset can still carry substantial risk. It explains diversification using the variance of an equally weighted…
The document clarifies notation for the Fama-French three-factor model and explains why subscripts and the intercept matter. A conventional time-series regression expresses an asset or portfolio’s excess return as an intercept plus its loadings on the market…
The discussion distinguishes the two-stage Fama–MacBeth procedure from a linear factor model implementation. In the procedure described, asset betas are first estimated, potentially with a rolling window, then a separate cross-sectional regression is run for…
The discussion explains that a linear factor asset-pricing model can, in principle, be applied to any asset return, including an individual stock. In practice, single-stock factor betas estimated from time-series regressions can be imprecise because company…
The document discusses implementing the nine Piotroski F-score signals with company financial data. The response treats the questions as accounting and data-mapping issues, and recommends consulting the original research for precise definitions. It suggests…
The document compares traditional asset-class risk premia with factor investing and alternative risk premia (ARPs). It frames factors as return sources within established markets, such as equity value, size, momentum, and quality, which may have different…
The document explains how to read regression coefficients in the Carhart four-factor model. A significant positive or negative coefficient indicates that a portfolio’s returns have a corresponding relationship with a factor after accounting for the other…
The document asks how to compare company performance while reducing the influence of macroeconomic changes such as interest rates, crises, and inflation. It also raises the idea of expressing company financial metrics relative to other companies instead of…