Explore the realities of securities trading beyond idealized models with ‘Market Liquidity Theory, Evidence, & Policy 2E’ by Foucault, Pagano, and Röell. This essential guide delves into the determinants and effects of market liquidity, recognizing that real-world trading involves imperfect information and diverse participant presence. Discover how order flow, a mix of information and noise, shapes price discovery and leads to deviations from fundamental value. Using market microstructure analysis, this second edition offers updated insights into recent market structure changes, financial regulation, and the critical relationship between financial instability and liquidity. New chapters examine algorithmic and high-frequency trading, making this a comprehensive resource for understanding modern security markets, their malfunctions, and their evolution.