We survey the nascent literature on machine learning in the study of financial markets. We highlight the best examples of what this line of research has to offer and recommend promising directions for future research. This survey is designed for both financial economists interested in grasping...

This paper provides an alternative real options framework to assess how firms' strategic interaction under imperfect competition a¤ects the industrial dynamics of investment, concentration, and expected returns. When firms have similar production technologies, the cross sectional variation in...

We study sources and implications of undiversified portfolios in a production-based asset pricing model with financial frictions. Households take concentrated positions in a single firm exposed to idiosyncratic shocks because managerial effort requires equity stakes, and because investors gain...

Active equity funds care about fund size, affected by fund flows that obey a strong factor structure with the common component responding to macroeconomic shocks. Funds hedge against common flows by tilting their portfolios toward low-flow-beta stocks, while household/retail and index investors...

We develop a new class of tree-based models (P-Tree) for analyzing (unbalanced) panel data utilizing global (instead of local) split criteria that incorporate economic guidance to guard against overfitting while preserving interpretability. We grow a P-Tree top-down to split the cross section of...

The historical returns on equity index options are well known to be strikingly negative. That is typically explained either by investors having convex marginal utility over stock returns (e.g. crash/variance aversion) or by intermediaries demanding a premium for hedging risk. This paper examines...

When expected returns are linear in asset characteristics, the stochastic discount factor (SDF) that prices individual stocks can be represented as a factor model with GLS cross-sectional regression slope factors. Factors constructed heuristically by aggregating individual stocks into...

We analyze the financial performance of a hypothetical portfolio of 120 mRNA vaccine candidates in the preclinical stage targeting 11 emerging infectious diseases. We calibrate the simulation parameters with input from domain experts in mRNA technology and an extensive literature review. We find...