What is 'Red September'? The Bitcoin Curse and Why Wall Street Can't Escape It

Bitcoin has fallen 8 times in the past 13 Septembers. Since 1928, the U.S. stock market has also suffered from the same issue.

Written by: Jose Antonio Lanz

Compiled by: Baihua Blockchain

Bitcoin investors have lost money 8 times in the past 13 Septembers. The average performance of the S&P 500 in September has been negative since 1945, and researchers at Yardeni have traced this pattern back to 1928.

Bitcoin is not the originator of this curse, but it has not been spared either.

Crypto traders refer to it as 'Red September,' a cyclical market 'nightmare' that resurfaces every year at this time. However, this is not superstition but a stubborn data pattern that neither a 15-year-old asset nor a century-old index can escape.

What is the reason behind it?

Data Supporting the Curse

According to monthly return data tracked by CoinGlass, Bitcoin has recorded declines in September 8 times out of 13 complete years since 2013, with a win rate of only 38.5%. The average return rate is -2.97%, and the median is -2.44%. Both of these figures are crucial: a negative median means that even in 'normal' Septembers, losses occur, not just a few crashes dragging down the average.

Only June's performance comes close to this dismal situation, with an average decline of a relatively small 1.59%. The average returns for the remaining months on the calendar are all positive. In contrast, October is the most profitable month of the year, with an average return rate of 19.92% and a median of 14.71%, which is the origin of the 'Uptober' market that the crypto community praises every year at this time.

August's data deserves special mention because it appears deceptive: the average return rate for August seems to be as high as 2.82%, but the median return rate is -6.99%. In other words, the vast majority of Augusts are losses, with only a few extreme years of soaring returns pulling the average into positive territory.

Not Limited to the Crypto Circle

Wall Street has recorded this phenomenon for a longer time and in more detail. JPMorgan's proprietary market research shows that since 1945, the average decline of the S&P 500 in September is about 0.6%, making it the only month with a long-term average return that is negative. If the span is extended to 1928, the data is even worse, with an average decline approaching 1.1% to 1.2%.

There are various theories about the causes: mainstream views include that mutual funds typically end their fiscal year on October 31, leading to concentrated selling of losing positions in September for tax-loss harvesting; institutional traders return from summer vacations and execute previously postponed hedging reductions; additionally, the Federal Reserve's mid-month meetings often coincide with the most volatile points.

None of these theories perfectly explain Bitcoin—Bitcoin has neither a fiscal year nor summer vacations, yet it remains a financial investment asset.

This year adds a layer of special variables: 2026 is an election year in the U.S. In the past 10 midterm election cycles since 1986, the average annual low for the U.S. stock market often falls on September 2, with the average drawdown before the market stabilizes and rebounds approaching 17% from previous highs. Given that Bitcoin's current trading characteristics are more akin to high Beta tech stocks rather than purely safe-haven assets, this correlation is bidirectional.

What Happened Last September

Last year (2025), 'Red September' initially played by the rules, then staged a dramatic reversal. Bitcoin opened the month near $108,000, with the RSI indicator falling into the oversold zone around 38. Ben Kurland, CEO of DYOR, even told Decrypt that 'Red September' is more of a 'myth than a mathematical rule.'

The early market conditions still followed historical patterns. By mid-month, a brutal weekly market wiped out nearly $162 billion from the total market cap of crypto, with Bitcoin dropping to $112,000, hitting a low of $111,986 during the day. At that time, traders in the prediction market were betting on the probability of another bearish candle approaching 60%.

However, Bitcoin then launched a strong rebound, with ETF inflows playing a crucial role. CryptoQuant viewed long-term holders transferring tokens to ETFs as a bullish signal, and Bitcoin strongly rebounded, breaking through $114,000, ultimately closing the month up 5.16%, marking the third consecutive green September on record.

Then October Destroyed the Celebration

The rebound lasted only six days. On October 6, Bitcoin hit a historic high of over $126,000, and the market's expectations for the 'Uptober' rally seemed solid.

However, reality took a sharp turn. On October 10, U.S. President Donald Trump threatened to impose a 100% tariff on Chinese imports, and the crypto market became the only place trading and reacting. Within 24 hours, $19 billion in leveraged positions evaporated, and 1.6 million traders were liquidated. Market maker Wintermute even stated that it completely halted trading as the extreme volatility directly breached internal risk control indicators.

On that day, Bitcoin plummeted from above $121,000 to below $102,000, with altcoins suffering even more, as some Layer-2 tokens lost 70% of their market value within hours. October ultimately closed down 3.69%, becoming the third October to close down since 2013. The market continued to deteriorate: November plummeted 17.67%, marking the worst November since 2018, and in June this year, it plunged to around $59,300, a 21-month low. Crypto traders referred to this period as the crypto winter.

Thus, last year was an abnormal year: the market experienced a 'Green September' (Uptember) and a 'Red October,' completely contrary to historical norms.

Current Market Dynamics of Bitcoin

Entering September 2026, Bitcoin is trading around $77,500. Prior to this, Bitcoin had just closed August with a nearly 25% increase—its best August performance since 2021. The current upward momentum is encountering resistance below the resistance levels of $81,455 to $82,538, while the support range is between $73,670 and $75,157.

Since spring this year, the macro environment has undergone a drastic change. Federal Reserve Chairman Kevin Warsh warned at the first Jackson Hole annual meeting that the PCE price index is running at an annual rate of 3.7% and has shown acceleration over the past six months; the CME FedWatch tool shows that the probability of a rate hike in September is currently at 68.2%. Meanwhile, the 30-year U.S. Treasury yield reached 5.28% at the end of August, the highest since the 2008 financial crisis.

Gold has recently moved in sync with Bitcoin, revealing the true driving force: it is not merely an increase in risk appetite, but an escalating 'currency devaluation hedge trade'—investors are betting that in the face of persistent inflation, the Federal Reserve will ultimately be forced to continue printing money. Additionally, the SEC's release of the 'Regulation Crypto Assets' on August 18 provided rare regulatory good news for the currently tense market sentiment.

The next hardcore test will be on September 15-16, when the Federal Reserve will decide whether to initiate the first rate hike since the tightening cycle of 2022-2023—precisely that tightening cycle led to Bitcoin's plunge of about 65%, hitting a deep low of $15,500 in November 2022.