Market betas have a strong and positive relation with average stock returns on a handful of days every year. Such unique days, defined as leading earnings announcement days (LEADs), are times when an aggregate of influential S&P 500 firms disclose quarterly earnings news early in the earnings season. The positive return-to-beta relation holds for various test portfolios, individual stocks, and Treasuries; and is robust to different data frequencies and testing procedures. On days other than LEADs, the beta-return relation is flat. We conclude that waves of early earnings announcements by large firms clustered on LEADs significantly influence asset pricing.

This study attests to the important role of US midterm elections in asset pricing, even more important than presidential elections. In months following the midterms, equity premiums, mutual fund flows, and real investment growth rates are significantly higher and Treasury premiums are lower. This is consistent with theoretical models relating higher asset prices to lower future discount rates when post-election political uncertainty decreases. The results are robust to different measures of uncertainty. Also, market betas relate positively to the cross section of average returns in post-midterm months, but the relation is flat in other months.