Bitcoin’s September Surge Challenges a Decade of Monthly Performance Trends

Bitcoin is approaching its third consecutive monthly gain, which would mark a break from a September pattern that has persisted since 2013. Still, the cryptocurrency could face a different environment in the fourth quarter as Treasury yields and oil prices remain elevated and two major November events approach.

Bitcoin has gained roughly 7% in September after advancing 25% in August. Since 2013, every year with a positive August was followed by a negative September. With only two calendar days left, a positive monthly close would end that streak and give bitcoin three straight monthly gains from July through September.

The performance would also push bitcoin’s third-quarter return above 40%, marking its first quarterly advance since Q3 2025.

Q4 Starts With a Volatile Macro Backdrop

The fourth quarter has historically been bitcoin’s strongest period. According to CoinGlass, bitcoin has posted an average Q4 gain of about 77%.

Bitcoin is currently trading around $84,000, but rising bond yields are creating a more uncertain backdrop. Global yields have moved higher, while the U.S. 10-year Treasury yield is now above 5.2%.

The MOVE index, which measures expected volatility in the Treasury market, has also climbed above 100 and is approaching its year-to-date highs.

Oil prices are adding to inflation concerns, with crude holding above $90 a barrel. Gold also came under pressure Monday, falling around 3% to just above $4,000 an ounce.

November Could Test Risk Appetite

Two developments in November could further affect liquidity and investor positioning.

Anthropic has reportedly been preparing for a possible November IPO. A major listing could attract attention and capital from investors, although the timing and size of the offering have not yet been confirmed.

The U.S. midterm elections are also scheduled for November and could introduce additional uncertainty as investors evaluate the potential policy outlook.

Bitcoin therefore enters Q4 with strong recent performance and favorable historical seasonality, but higher yields, oil prices and upcoming events could determine whether that momentum continues.