Skip to content ETFs Review Our ETFs Start an ETF 1042 QRP About Firm Team Research Blog “Best Of” Blog Academic Research Books New? Start Here Search When Everyone Trades the Same Factor Playbook For decades, academic researchers have catalogued hundreds of patterns in the stock market — statistical regularities linking firm characteristics to future returns. These persistent return patterns, unexplained by standard risk models, are known as  anomalies . They now form the intellectual backbone of a multi-trillion-dollar industry called factor investing, implemented through mutual funds, hedge funds, and ETFs worldwide. The premise is straightforward: buy stocks with characteristics associated with high returns (the right, or “long leg”) and short stocks with characteristics associated with low returns (the left, or “short leg”).…