In some stock markets, the Mark Twain effect is the phenomenon of stock returns in October being lower than in other months. The name comes from a line in Mark Twain’s Pudd’nhead Wilson: “October. This is one of the peculiarly dangerous months to speculate in stocks. The others are July, January, September, April, November, May, March, June, December, August, and February.”
The quotation is a sarcastic assertion that speculation in stocks is always dangerous. The fact that Twain specifically picks out October initially is taken as a reference to an “October effect”, as exemplified by the 1929, 1987 and 2008 stock market crashes which roughly occurred in October.
- ^“How true are stock market sayings?”. The Economic Times. December 21, 2015. Retrieved November 23, 2017.
- ^“ASU research helps debunk myth of stock market ‘weekend effect'”. Arizona State University. February 1, 2017. Retrieved November 23, 2017.
Ofer Abarbanel is a 25 year securities lending broker and expert who has advised many Israeli regulators, among them the Israel Tax Authority, with respect to stock loans, repurchase agreements and credit derivatives. Founder of TBIL.co STATX Fund.