Foreign media report that the Bitcoin market’s commonly cited “Red September” is not merely an emotional label. According to CoinGlass, since 2013, Bitcoin has closed lower in 8 out of 13 complete Septembers, with an average decline of 2.97% and a median decline of 2.44%. The article suggests this indicates that September’s weakness is not merely the result of extreme years.
Bitcoin historically weak in September
Among the monthly data listed, September had the worst average and median returns for Bitcoin. In contrast, October has historically performed best, with an average return of approximately 19.92% and a median return of 14.71%, which is why the market often refers to it as "Uptober."
The article also noted that August data showed divergence: although the average return was positive, the median was negative, indicating that most years saw weak performance in August, with overall averages being pulled up by a few years of significant gains.
The same phenomenon occurs in U.S. stocks.
The article argues that this phenomenon is not unique to the crypto market. According to long-term Wall Street statistics, the S&P 500 has historically averaged a decline of about 0.6% in September since 1945, and the average decline is even higher when extending the timeframe back to 1928.
There is no unified explanation for the cause, but the article mentions several common theories, including mutual funds managing losing positions before the end of their fiscal year, institutions consolidating risk adjustments after the summer, and the Federal Reserve’s typical interest rate meeting in mid-September, which can amplify volatility.
The article also notes that 2026 is another U.S. midterm election year. Reviewing the 10 midterm election cycles since 1986, the average trough for U.S. stocks occurred in early September, with a decline of nearly 17% from the previous peak. In the author’s view, Bitcoin’s recent trading characteristics are more similar to high-volatility tech stocks, making it more susceptible to shifts in similar risk appetite.
In October last year, liquidations amplified the downturn.
The article review noted that in September 2025, the historical trend of "Red September" was briefly broken. Bitcoin ended the month up 5.16%, marking its third consecutive September gain, with ETF inflows considered one of the supporting factors.
However, this rebound did not last long. According to the article, after Trump threatened to impose 100% tariffs on Chinese imported goods on October 10, 2025, the crypto market reacted immediately, with approximately $19 billion in margin positions liquidated within 24 hours and around 1.6 million traders liquidated. Bitcoin dropped from above $121,000 to below $102,000 on that day, ending October down 3.69%.
Watch the Fed meeting in September
The article states that Bitcoin traded at approximately $77,500 in early September 2026, with a cumulative gain of nearly 25% for August, but encountered resistance near $81,000 to $82,500 in the short term, with support located in the range of $73,700 to $75,200.
The author believes that the key variable facing this September market cycle remains the macroeconomic environment. The article notes that the Federal Reserve’s meeting on September 15–16 will determine whether it undertakes its first interest rate hike since 2023, and the CME FedWatch tool indicates that market expectations for a September rate hike have clearly intensified. The article also mentions that the U.S. 30-year Treasury yield rose to 5.28% at the end of August, signaling that the interest rate environment continues to tighten.
The article also notes that gold and bitcoin have recently strengthened in tandem, reflecting that some capital is increasingly focused on inflation and currency purchasing power, rather than just changes in traditional risk appetite. Overall, the author believes that "Red September" is more of a seasonal phenomenon that repeatedly appears in long-term data, rather than mere market superstition.