Wall Street’s “sell in May and go away” mantra is back in focus as markets approach what’s widely seen as the weakest stretch of the year, but fresh data suggests the seasonal playbook may be badly outdated.
Bank of America’s chief technical strategist Paul Ciana challenged the decades-old rule this week, saying historical trends show equities often hold up through early summer rather than rolling over immediately.
BofA Just Killed The Sell In May Trade: Here’s What Replaces It
First, Ciana ran the numbers on every six-month rolling window for the S&P 500 since 1928.
May through October is indeed the weakest stretch on the calendar — up 66% of the time with a 2.47% average return. November through April is the strongest, up 70% of the time with a 5.20% average.
So far, so familiar.
But the weakness is not where the saying suggests.
S&P 500 Seasonality (6-Month Periods)
| 6-month period | Avg Return | Median Return | % Time Up | Avg Drawdown | Median Drawdown |
|---|---|---|---|---|---|
| Jan – Jun | 3.85% | 5.01% | 65.3% | -7.60% | -5.92% |
| Feb – Jul | 3.98% | 4.56% | 68.4% | -7.90% | -4.85% |
| Mar – Aug | 4.98% | 4.94% | 70.4% | -7.58% | -5.39% |
| Apr – Sep | 3.54% | 3.94% | 66.3% | -7.79% | -4.29% |
| May – Oct | 2.47% | 3.35% | 66.3% | -8.67% | -5.21% |
| Jun – Nov | 3.63% | 4.58% | 66.3% | -8.31% | -5.24% |
| Jul – Dec | 4.25% | 5.52% | 68.4% | -8.28% | -4.93% |
| Aug – Jan | 3.66% | 4.95% | 66.0% | -8.68% | -5.68% |
| Sep – Feb | 3.06% | 5.00% | 63.9% | -8.56% | -5.29% |
| Oct – Mar | 4.69% | 5.92% | 62.9% | -7.65% | -4.94% |
| Nov – Apr | 5.20% | 5.39% | 70.1% | -6.76% | -4.11% |
| Dec – May | 4.29% | 4.63% | 66.0% | -7.28% | -4.60% |
When Ciana broke the period into three-month windows, the picture flipped.
June through August is actually the second-strongest three-month stretch of the year, returning 3.30% on average.
The pain is back-loaded into August through October, which is the only three-month period since 1928 with a negative average return at -0.02%.
“While May-Oct does have the lowest average 6-month return, it is back-end loaded to the Aug-Oct period,” Ciana said.
The expert indicated investors probably shouldn’t follow the classic “sell in May and go away” playbook, adding that a better strategy may be “to sell in August and buy again by Halloween.”
S&P 500 Seasonality (3-Month Periods)
| 3-month period | Average return | Median return | % of time up | Average correction | Median correction |
|---|---|---|---|---|---|
| Jan – Mar (1Q) | 1.64% | 2.10% | 60.20% | -5.28% | -3.74% |
| Feb – Apr | 1.50% | 2.28% | 67.35% | -5.51% | -3.87% |
| Mar – May | 2.02% | 2.61% | 61.22% | -5.64% | -2.97% |
| Apr – Jun (2Q) | 2.38% | 2.24% | 60.20% | -5.34% | -3.60% |
| May – Jul | 2.46% | 2.04% | 64.29% | -5.35% | -2.97% |
| Jun – Aug | 3.30% | 2.45% | 65.31% | -5.08% | -3.36% |
| Jul – Sep (3Q) | 1.39% | 2.91% | 60.20% | -5.39% | -2.92% |
| Aug – Oct | -0.02% | 0.90% | 55.10% | -7.38% | -5.31% |
| Sep – Nov | 0.55% | 2.45% | 64.29% | -7.40% | -4.87% |
| Oct – Dec (4Q) | 2.89% | 4.63% | 74.49% | -5.66% | -3.52% |
| Nov – Jan | 3.57% | 4.17% | 67.01% | -4.56% | -2.25% |
| Dec – Feb | 2.45% | 2.50% | 62.89% | -4.58% | -3.63% |
| Averages | 2.01% | 2.49% | 63.54% | -5.59% | -3.59 |
Why May Tends to Favor The Nasdaq 100 Specifically
If there is a single trade that BofA’s seasonal heatmap flagged as the strongest in May, it is long the Nasdaq 100 – as tracked by the Invesco QQQ Trust (NASDAQ:QQQ).
The index has averaged a +2.19% gain in May since 1986, rising 68% of the time — and the trend has been more pronounced since 2016.
Ciana noted that even in 2018 — the second year of President Donald Trump‘s first term, a setup that historically drags equities — the NDX defied the pattern and rallied.
That matters now because 2026 is also Year 2 of the presidential cycle.
Photo: Pla2na/Shutterstock
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