The Overnight Return Premium

Most traders think about equities in daily bars, but some of the market's most persistent behavior is hidden inside the day itself. This book is written for systematic traders, quantitative researchers, and technically minded investors who want to understand why close-to-open returns can behave so differently from open-to-close returns-and how to study, forecast, and trade that difference with institutional rigor. Readers will learn how to decompose equity returns into overnight and intraday components, engineer clean session-level data, and avoid the measurement errors that quietly ruin time-of-day research. The book then moves from evidence to action: it examines the empirical case for the overnight premium, the economic forces that may sustain it, the signals and factor exposures that help predict it, and the portfolio construction, execution, and cost modeling required to capture it in practice. Just as importantly, it shows how to backtest these strategies correctly, control bias and overfitting, and manage gap risk, tail exposure, and implementation frictions. Practical throughout, the book treats overnight trading not as a curiosity but as a full research and deployment discipline. A background in basic statistics, equity markets, and systematic strategy design will help, but the presentation is structured to take readers from first principles to live-trading considerations in a clear, professional sequence.