Summer Seasonality (May-October)
Sell in May and go away?
The November-April period has historically outperformed May-October by approximately 6% annualized since 1950. However, May-October returns are still positive on average (+3% annualized). 'Sell in May' is an oversimplification of a real but weak seasonal pattern.
| Date | 1M return | 1Y return | 5Y return |
|---|---|---|---|
| 2014-05-01 | +2.2% | +11.9% | +56.4% |
| 2015-05-01 | +0.1% | -1.3% | +34.8% |
| 2016-05-02 | +0.9% | +14.9% | +100.1% |
| 2017-05-01 | +1.0% | +11.2% | +74.0% |
| 2018-05-01 | +1.9% | +9.9% | +54.1% |
| 2019-05-01 | -5.9% | -0.4% | +73.2% |
| 2020-05-01 | +8.8% | +48.1% | +98.9% |
| 2021-05-03 | +0.4% | -0.9% | — |
| 2022-05-02 | -1.3% | -1.6% | — |
| 2023-05-01 | +0.3% | +20.4% | — |
| 2024-05-01 | +5.2% | +12.6% | — |
What history says
Editorial commentary written by ALAN analysts. Figures cited below are analyst-authored context — they are not derived from the chart above and may reflect different windows or sources.
After transaction costs, taxes, and the risk of missing occasional strong summers (2020, 2023), mechanically selling in May has not outperformed buy-and-hold on an after-tax basis.
If you need to raise cash or reduce risk for any reason, doing so in May rather than November puts the odds slightly in your favor. But don't sell a good portfolio purely for seasonality.
In presidential election years, the summer tends to be stronger than normal due to policy uncertainty resolution and campaign stimulus promises. 2024 followed this pattern.
If you already need to raise cash for a known expense, the historical November-April edge argues mildly for doing it in spring rather than autumn — but selling a well-built portfolio purely for the season has not paid once taxes and the occasional strong summer are counted.