We hypothesize that when investors pay less attention to financial markets, they rationally allocate relatively more attention to market-level information than to firm-specific information, leading to increases in stock return co-movements. Using large jackpot lotteries as exogenous shocks that attract investors’ attention away from the stock market, we find supportive evidence that stock returns co-move more with the market on large jackpot days. This effect is stronger for stocks preferred by retail investors and is not driven by gambling sentiment. We also find that stock returns are less sensitive to earnings surprises and co-move more with industries on large jackpot days.

We provide a psychological explanation for the delayed price response to news about economically linked firms. We show that the return predictability of economically linked firms depends on the nearness to the 52-week high stock price. The interaction between news about economically linked firms and the nearness to the 52-week high can partially explain the underreaction to news about customers, geographic neighbors, industry peers, or foreign industries. We also find that analysts react to news about economically linked firms but the 52-week high effect reduces such reactions, providing direct evidence that the 52-week high affects the belief-updating process.

We use data on signed option volume to study which components of option volume predict stock returns and resolve the seemingly inconsistent results in the literature. We find no evidence that trades related to synthetic short positions in the underlying stocks contain more information than trades related to synthetic long positions. Purchases of calls that open new positions are the strongest predictor of returns, followed by call sales that close out existing purchased call positions. Overall, our results indicate that the role of options in providing embedded leverage is the most important channel why option trading predicts stock returns.