The fall period is no stranger to volatility. Money managers are well versed in the September Effect1: which circles the calendar month as the only one with a negative return over the past 100 years. Then there’s October, which has been positive over the past century, despite notching up an impressive array of market crashes: 1907, 1929, 1987, 2001, and 2008, to name just five. Both reputations, however, are often viewed as historical quirks, attributed by many to seasonal behavioral biases as investors cash in on gains at the end of the summer.