October may not be the cruelest month for investors — based on the averages, that’s September. But when Wall Street stumbles at this point of the year, it stumbles extra hard. And that’s why, in the Oct. 3 episode of Motley Fool Answers, Alison Southwick and Robert Brokamp are joined by former Fool Morgan Housel to kick off a four-part series on the history of market crashes in the United States, with a discussion of the big one, the Great Depression.