The first essay is the result of work with Paul Borochin. We perform the first large-sample estimation of the Volume Synchronized Probability of Informed Trading (VPIN) measure on the NYSE TAQ universe, enabling us to test the validity of VPIN with high statistical power and to do traditional asset pricing tests of informed trading. Informed trading measured by VPIN is priced, and is not explained by firm characteristics such as volume, volatility, or liquidity, supporting the validity of the measure. Additionally, we create a novel signed version of VPIN (SVPIN) to identify the direction of informed trades. A portfolio long low-VPIN stocks and short high-VPIN ones delivers a monthly five-factor alpha of .18%, which rises to .29% when using...