January Barometer: Trading on January Equity Returns

Summary

The January Barometer proposes using an equity index’s January return to guide exposure for the remaining eleven months. A positive January signals holding equities; a negative one signals moving to Treasury bills. The document also describes a long-bond alternative and reports that the source paper, using 152 years of U.S. market data, found the equity-and-bills rule performed better over that sample than passive equity exposure and several January-based alternatives.

The evidence is contested. The document warns that a long-short version can enter damaging short positions during bull markets and that the rule was exposed to four of the five worst post-January intervals in the long historical test. Other cited studies find weak or insignificant results across countries, styles, and later periods, and report that the effect may not beat buy-and-hold after risk adjustment. The proposed pattern has no strong fundamental explanation and may reflect data mining or the long-run upward drift of equities. Its historical results therefore do not establish a persistent or useful forecasting edge.

Key ideas

• A positive January return is used as a signal to hold equities for the following eleven months.
• The described simple rule shifts to Treasury bills after a negative January.
• The source paper reports stronger historical results for the equity-and-bills rule than for several alternatives.
• Long-short timing can incur severe losses when it shorts during bull markets.
• Other research questions the effect’s significance, persistence, and value relative to buy-and-hold.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.