So, today is the day. An unlucky day, some would have it (although nobody is quite sure why or when it became so). Black cats, broken mirrors etc.
Theres a branch of financial economics that looks at the effect of superstition on the stock market. It has a somewhat different story to tell about Friday the 13th, which is that the effect is perhaps different. There is a large literature on F13 in health, especially mental health which I dont review here but the papers noted below do reference.
- Lucey, Brian M., Friday the 13th: International Evidence (June 2000). maybe there is REVERSE effect and returns are greater…published as Friday the 13th: International evidence (2001) Applied Economics Letters, 8 (9), pp. 577-579
- Coutts, J.A. Friday the thirteenth and the financial times industrial ordinary shares index 1935-94 (1999) Applied Economics Letters, 6 (1), pp. 35-37. ; there is an effect in the UK but its muted
- Keefe, S and Mohammed, K (2011) The friday the thirteenth effect in stock prices: international evidence using panel data (its mixed)
- Auer, Benjamin R. and Rottmann, Horst, (2013) Is There a Friday the 13th Effect in Emerging Asian Stock Markets? (its muted)
What is the story? If we look at the SP500 from 1928 to now on the 148 occourances of Friday the 13th the average return falls to 0.011%, still positive but statistically different from both the average daily return of 0.02% and especially from the normal friday return.