Sectors and factors in August and September are mixed bag
Key points
- August and September can be challenging months for stocks in general
- Sector and factor performance is also very hit-or-miss during this time
- Materials, Industrials, and Technology have been the worst August/September performers since WWII
Sectors and Factors in August and September
In this article, we noted the overall stock market's tendency to exhibit greater weakness during August and September than at any other time of year.
The table below displays the percentage of years when a given sector/factor showed a net price gain from the end of July to the end of September and the cumulative percentage return achieved by holding it only during these two months every year since 1946.

These results are not much to write home about. Even the apparent "top performers" (Utilities and Telecommunications) have struggled mightily in recent years during August and September, as seen in the charts below.


These two "best" sectors were pretty reliable in August/September performances into the late 1990s but have struggled mightily ever since.
A closer look at the cellar dwellers
The charts below display the hypothetical growth of $1 invested in the Materials, Industrials, and Technology sectors only during August and September every year since 1946.



So, should investors avoid these sectors during August and September? It's complicated. On a year-by-year basis, any of these sectors can perform exceptionally well during this supposedly "weak" two-month period.
What the research tells us…
No "advice" is built into or implied by the data presented above. For those inclined to hedge or raise cash as part of their investment plan, there appears to be some long-term utility in considering these actions during August and September. At the very least, investors with a longer-term outlook might "gird their loins" and adjust their expectations during these two months each year to more of a "hope for the best, prepare for the worst" attitude. Shorter-term traders should pay particular attention to price trends and not be shy about playing the short side of specific sectors if price weakness unfolds.
