The takeaway
Power Integrations Inc shows a pronounced seasonal pattern over 10 years of data — strongest in May (+5.1%) and softest in September (−3.6%).
Right now
In July, the stock has risen 70% of years, averaging +5.9%, about +3.7 pts better than the S&P 500.
The full picture
Power Integrations Inc's most dependable month has been May, higher in 9 of 10 years; September has been its least reliable, up just 30% of the time.
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Month by month
The stock's clearest edge over the S&P 500 lands in May (+4.4 pts); it has trailed the market most in September (−3.4 pts).
“vs S&P” is Power Integrations Inc’s average for a month minus the S&P 500’s average for that same month — isolating Power Integrations Inc’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, May has closed higher 100% of the time versus 90% across the last 10 years — the pattern is holding.
Figures are the typical (median) May return and how often it rose — the last 5 years versus the last 10(the heatmap’s default window). This verdict stays anchored to that 10-year window even if you zoom the chart, so it never disagrees with the badges above.
In plain English
Strip the year back and a single month does the heavy lifting: May, up in 9 of 10 Mays while the other eleven tend to blur together.
Its average (+5.1%) and median (+4.1%) land within a hair of each other — the tell of steady, year-after-year gains rather than one outlier doing the work. That reliability comes with real swings, mind — even May ranges by 9.0% from year to year, so any single year can land far from the average. Crucially, the gain is the stock's own rather than a rising tide's: May has cleared the S&P 500 by +4.4 points above the index. That consistency sets it apart from the field, where the average stock manages May only about 55% of the time.
The strength clusters rather than stands alone — May–July forms a firm stretch that carries much of the year. The weaker half of the year is plainer: September has been the soft spot — the weakest of 4 months that average a loss (−3.6%), and the edge isn't year-round — the stock has trailed the S&P 500 in September, March, and August. Its roughest month on record was a −18.8% November in 2025 — a reminder of how hard even a seasonal name can fall.
May has now closed higher 6 years running. Reassuringly, the tendency has held its shape: the recent five years still track the years behind them.
The takeaway is less about when to buy than what to expect: May aside, the stock's months offer little reliable tilt.
Short answers on the stock's best month (May), its worst (September), and whether it really trades seasonally.
Yes, to a pronounced degree. Since 2016 its best month (May, +5.1%) has run well ahead of its worst (September, −3.6%) — the heatmap above shows how steady that gap has been year to year.
May has been the strongest, averaging +5.1% and closing higher in 9 of 10 years since 2016.
It's the weakest, averaging −3.6% — historically a soft spot, though it still varies from year to year.
Explore
These names have the strongest July track records on record — a starting point for comparison.
Before you trade