RT Journal Article SR Electronic T1 A Flexible Theory of Price Momentum JF The Journal of Investing FD Institutional Investor Journals SP 36 OP 42 DO 10.3905/joi.2007.681822 VO 16 IS 1 A1 John S. Brush YR 2007 UL https://pm-research.com/content/16/1/36.abstract AB This article attempts to integrate complex and perhaps irrational investor reaction to price change into a formal model encompassing observed worldwide variations in price momentum. We review the theoretical and empirical underpinnings of price momentum in the U.S. and worldwide, observing that efforts to link or explain price momentum using other factors or risk measures generally fail, leaving an unexplained but statistically real phenomenon. Unlike value concepts which are found to work worldwide in the obvious high-relative-value-implies-excess-return way, price momentum seems to vary from country to country, seemingly defying any logical explanation. Worldwide, we observe that price momentum differs from country to country with regional themes suggesting that it is a cultural phenomenon. Using a collection of stylized outlier behaviors, we develop a story and simple model linking price momentum to perceived future attractiveness, based on traditional value ideas. A number of testable hypotheses, most confirmed by empirical work, flow from this model.TOPICS: Security analysis and valuation, statistical methods, global