Skip to content
Opinion
John Authers

Momentum Was a Thing in the 19th Century Stock Market, Too

The search for factors that provide dependably superior equity returns just got a valuable new weapon in a trove of historical data.

Getting reliable data as far back as the 1860s is no easy task.

Getting reliable data as far back as the 1860s is no easy task.

Photographer: FPG/Archive Photos/Getty Images

To get John Authers' newsletter delivered directly to your inbox, sign up here.

The work to find factors, or aspects of different stocks that will lead to persistent and predictable superior returns, has turned into an academic arms race in recent years. Literally hundreds of putative factors have been claimed in the literature. Many of them disappear once the factor has to survive “out-of-sample,” after the period during which the eager academics did their data-mining.