Semiconductors vs. S&P 500: Who Wins Seasonally?

Dear Investor,

You have probably noticed: semiconductor stocks are booming. The PHLX Semiconductor Index has gained 177.73 percent within a year at the time of writing.

The strong rise attracted many investors. Inflows into leveraged instruments were high, and in Korea it was primarily seniors who took on debt to buy semiconductor stocks.

Euphoria seems to be setting in. We are asking ourselves what comes next.

Seasonality provides an answer to this.

The seasonal race in the coming months

Take a look at the first chart. It shows you the seasonal pattern of the PHLX Semiconductor Index in blue. In gold you can see, for comparison, the seasonal pattern of the S&P 500. Both were calculated over the past 25 years.

Semiconductor Index, S&P 500, a seasonal pattern over 25 years

Seasonal pattern of the PHLX Semiconductor Index (blue) and the S&P 500 (gold) over 25 years, with Seasonax data
Semiconductors are seasonally weaker until early October. Source: Seasonax

As you can clearly see, semiconductor stocks are set to decline over the coming four months from a seasonal perspective. The broader market in the form of the S&P 500 also does not fare well during this period, as it is the weak summer season. However, its seasonal pattern is notably better than that of the Semiconductor Index.

Even stronger seasonal downtrend without the extreme phase

Bear in mind: the seasonal chart above also incorporates the most recent extreme bull run of the Semiconductor Index. When a phase like 2025/26 is exceptionally strong for the Semiconductor Index, it correspondingly pulls the seasonal average higher.

This raises the question of what the seasonal pattern of the Semiconductor Index looks like without this extreme phase. The next chart therefore shows you the seasonal pattern of the PHLX Semiconductor Index again from 2001, but this time excluding the years 2025 and 2026.

Semiconductor Index, a seasonal pattern without 2025/26

Seasonal pattern of the PHLX Semiconductor Index from 2001, excluding 2025 and 2026, with Seasonax data
The weakness is very pronounced. Source: Seasonax

You can now see how weak the seasonal pattern of the Semiconductor Index is during the coming summer months. The seasonal pattern through to the end of September is already genuinely weak without the influence of the most recent extreme rally.

The seasonal outlook for semiconductor stocks is negative

What will happen with semiconductor stocks over the coming months? Nobody can tell you that with certainty – the future is open. From a seasonal perspective, however, the probability of declines in the coming months is significantly elevated, particularly for semiconductor stocks.

Warm regards,

Dimitri Speck
Founder and Chief Analyst of Seasonax

PS: Make use of the filter and comparison functions of Seasonax!

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