If you're looking for seasonal trading patterns that actually hold up under scrutiny, Broadcom Inc. (AVGO) has one that's hard to ignore. For the past 16 years, the stretch from November 15 to December 15 has been remarkably kind to Broadcom shareholders.

According to Seasonax data, the stock has posted an average return of 8.9% during this one-month window. More impressively, it delivered gains in 14 of those 16 years—an 87.5% win rate that would make most traders jealous.

This isn't some flash-in-the-pan trend either. In 2023, Broadcom climbed 15.82% during the period. But 2024 was something else entirely: from November 15 to December 16, the stock exploded 51.66% higher, marking its best seasonal performance on record.

"Broadcom experiences a particularly steep seasonal rise before the turn of the year, with the steepest seasonal increase occurring in the first half of December," said Dimitri Speck, founder and chief analyst at Seasonax.

What Made 2024 So Exceptional?

Last year's rocket ride wasn't random. On December 11, 2024, Broadcom reported fiscal fourth-quarter results that blew past expectations, and the stock responded with a 24.4% single-day gain—the largest one-day percentage jump in the company's history.

The numbers behind that reaction were substantial. Revenue for the fiscal year reached a record $51.6 billion, powered by a 220% year-over-year surge in artificial intelligence-related income. The company also sweetened the pot by raising its dividend 11% to $0.59 per share for fiscal 2025 and issuing upbeat guidance for the first quarter.

It was the kind of earnings report that doesn't just beat estimates—it resets expectations entirely.

Can December Earnings Deliver Again?

With the next earnings report scheduled for December 11, 2025, traders are looking at Broadcom's track record of post-earnings moves during this quarter. The pattern has been overwhelmingly positive:

• Dec. 11, 2024: +24.4%
• Dec. 11, 2023: +9.00%
• Dec. 9, 2022: +2.4%
• Dec. 10, 2021: +8.27%
• Dec. 11, 2020: -1.03%

That's four out of five years with gains following fourth-quarter earnings announcements.

As of November 12, 2025, Broadcom has already gained 53% year-to-date. To put that in perspective, Nvidia Corp. (NVDA) is up 40% over the same period, while Advanced Micro Devices Inc. (AMD) has surged 114%. The iShares Semiconductor ETF (SOXX) has returned 38%, placing Broadcom ahead of the broader semiconductor pack but behind AMD's explosive run.

Quarterly earnings have consistently moved the needle this year. The stock jumped 9.4% on September 5 after third-quarter results and surged 8.6% on March 7 following first-quarter numbers. The only disappointment came in June, when shares dipped 5% on second-quarter results.

Here's what really matters: Broadcom has beaten analyst earnings estimates every single quarter since mid-2020. That's a streak that builds confidence, especially heading into a seasonally strong period.

Is There Anything Left in the Tank?

The obvious question is whether the rally has already played out. After a 53% year-to-date gain and sky-high expectations going into earnings, you might wonder if traders have already priced in the good news.

History suggests otherwise. Even in years when Broadcom has posted strong gains heading into this period, the seasonal pattern has held. While 2024 set an extremely high bar, the combination of consistent earnings beats, growing AI momentum, and a reliable seasonal trend keeps the probability tilted toward another December push.

Of course, past performance doesn't guarantee future results. But when a pattern works 87.5% of the time over 16 years, it's worth paying attention to—especially when the fundamental story still has legs.