The stock market usually booms in the November-to-April stretch. This indicator suggests otherwise.

The "best six months" seasonal pattern — the November-to-April stretch that has historically produced the bulk of the stock market's gains — may not hold this time, according to strategist Jim Paulsen. He points to lagged economic indicators, which he says suggest the usual seasonal tailwind could be absent in the current cycle.

Paulsen backtested his model to 1970 and found that when those lagged indicators were in a similar position, returns during the November-to-April window were meagre rather than strong. That is a notable caveat for investors who treat seasonal patterns as a reliable roadmap.

The takeaway is not that seasonality is broken, but that it is conditional. Seasonal tendencies describe averages across many years; they can be overwhelmed by the broader economic backdrop. What to watch: whether the lagged indicators Paulsen cites continue to weaken or begin to recover, and whether the market's actual performance diverges from the historical seasonal script. Treat seasonality as one input among many, not a standalone signal.