# WSJ Article Subject Tags

1. Motivation This post investigates the distribution of subject tags for Wall Street Journal articles that mention S&P 500 companies. e.g., a December 2009 article entitled, When Even Your Phone Tells You You're Drunk, It's Time to Call a … [Continue reading]

# Randomized Market Trials

1. Motivation How much can traders learn from past price signals? It depends on what kind of assets sell. Suppose that returns are (in part) a function of $K = \Vert {\boldsymbol \alpha} \Vert_{\ell_0}$ different feature-specific … [Continue reading]

# Notes: Ang, Hodrick, Xing, and Zhang (2006)

1. Introduction In this post I work through the main results in Ang, Hodrick, Xing, and Zhang (2006) which shows not only that i) stocks with more exposure to changes in aggregate volatility have higher average excess returns, but also that ii) … [Continue reading]

# Using the Cross-Section of Returns

1. Introduction The empirical content of the discount factor view of asset pricing can all be derived from the equation below: \begin{align} 0 = \mathrm{E}[m \cdot r_n] \quad \text{for all } … [Continue reading]

# Phase Change in High-Dimensional Inference

1. Introduction In my paper Feature Selection Risk (2014), I study a problem where assets have $Q \gg 1$ different attributes and traders try to identify which $K \ll Q$ of these attributes matter via price changes: \begin{align} \Delta p_n &= … [Continue reading]