However, there is a part of this story that is rarely mentioned when that nickname is repeated every year: the last three consecutive Septembers have actually yielded profits. The pattern that was once quite consistent has shown signs of breaking, and the reasons are structurally sound.
This article presents the complete data, the position of September 2026 so far, and more importantly, how to read seasonal data without falling into the trap of treating it as a forecast.
Key Takeaways
- The average Bitcoin return in September from 2013 to 2025 was minus 4.02%, with a median of minus 4.72%.
- Of the 13 recorded Septembers, 8 ended negatively and 5 positively. This is a poor ratio, but far from a certainty.
- The last three Septembers were all positive: 2023 was up 4.00%, 2024 was up 7.25%, and 2025 was up 5.36%.
- September 2026 is practically flat so far. Bitcoin is at US$77,459 as of September 14, down about 0.6% from the September 3 level of US$77,934.
- Retail interest is actually at its lowest point of the year, with Google searches for "Bitcoin" falling below the levels seen during the 2022 to 2023 bear market.
Complete Data: Bitcoin Returns Each September
Average: minus 4.02%. Median: minus 4.72%. Positive: 5 out of 13. Negative: 8 out of 13.
This average is the most frequently cited figure, and it certainly looks convincing. But take a closer look at the distribution. The two worst years—2014 with a minus 18.59% and 2019 with a minus 16.36%—significantly drag the average down. Excluding those two years, the average for the remaining 11 years sits at around minus 2.2%, still negative but much narrower.
This is why the median is more informative than the average for data like this, and why labeling September as a "gloomy month" without looking at the distribution oversimplifies the picture.
The Rarely Mentioned Part: The Last Three Years Were All Positive
Out of 13 years of data, the last three consecutive years have broken the pattern: 2023 was up 4.00%, 2024 was up 7.25%, and 2025 was up 5.36%.
This is no minor coincidence. Three consecutive years in the same direction is the second-longest streak in this dataset, following the negative streak from 2017 to 2022. And all three occurred precisely during the period when Bitcoin's market structure underwent its most significant changes.
Why the pattern is weakening. Seasonal patterns persist as long as the composition of market participants remains relatively stable. When spot Bitcoin ETFs launched in January 2024, that composition changed fundamentally. The institutional capital entering through ETFs has allocation schedules, mandates, and investment horizons that are entirely different from the retail behavior patterns that once shaped this seasonality.
Cumulative inflows into US spot Bitcoin ETFs have reached tens of billions of dollars since launch. When the largest source of demand in the market doesn't care what month it is, it's natural for monthly patterns to weaken.
September 2026 So Far
Bitcoin was trading at US$77,459.32 on September 14, 2026. For comparison, on September 3, the price was US$77,934.11. This means that for the first two weeks of September, Bitcoin has been practically flat, with a decline of about 0.6%.
Context is also important: August 2026 was a very strong month for Bitcoin, with a gain of around 25%. After such a significant rise, flat movement in the following month looks more like consolidation than a reversal.
It is worth noting that September 2026 is not over yet. Two major events are still pending in the second half of the month: the FOMC decision on September 16 and the CLARITY Act vote on September 15. Both carry far more weight regarding price direction than any seasonal factor.
Trending Data: Retail Attention at an All-Time Low
There is one data point far more interesting than seasonal patterns for understanding September 2026, and it comes from an unusual place: search engines.
Global search interest for crypto-related keywords is in the 26 to 30 range on a 100-point scale according to Google Trends, down about 70 points from its peak of 100 in August 2025. More strikingly, global searches for "Bitcoin" are now below the levels recorded during the 2022–2023 bear market, when Bitcoin's price was around US$16,000.
Compare this to current price conditions. Bitcoin at US$77,459 is still about four to five times higher than the 2022 bear market lows, yet public attention is lower than it was back then.
This is a historically unusual disconnect. For years, search interest moved almost in lockstep with price. Now, they are moving independently.
Sentiment indicators actually suggest something different. The Crypto Fear and Greed Index stood at 61, or the Greed category, on September 14, down from 63 the day before and 73 a week ago, but well above the 29, or Fear category, of a month ago.
This combination creates an unusual picture: market sentiment indicators show greed, while public attention has vanished. The most plausible explanation is that sentiment indicators largely measure volatility, volume, and market dominance, which are currently driven more by institutional flows, whereas Google searches measure retail attention, which is indeed absent.
How to Read Seasonal Data Without Getting Trapped
Seasonal data is useful, but only when placed in the right context. Here is the framework.
Treat it as context, not a signal. A negative September average tells us that, historically, this month tends to be weak. That is all. It does not tell us what will happen this September, because every September has its own unique macro conditions.
Check if the conditions that created the pattern still exist. Bitcoin's seasonal patterns were formed in an era when the market was dominated by retail. After ETFs changed the composition of market participants, the foundation of those patterns weakened. Three consecutive positive Septembers are proof of this.
Compare its weight against ongoing catalysts. In September 2026, there is an interest rate decision with an 85% to 90% probability of a hike and a crypto legislation vote in the US Senate. Seasonal factors carry far less weight than both of these.
Beware of confirmation bias. Nicknames like "Rektember" are catchy and fun to repeat, which makes them feel more accurate than they actually are. Data shows that 5 out of 13 Septembers ended positively, nearly 40%. That is not a figure that supports any certainty.
Position sizing is more important than direction. The investors who lose the most are not those who misread the direction, but those who take positions that are too large for the ongoing volatility. A more structured allocation framework is discussed in Beginner Crypto Portfolio.
Conclusion
September's reputation as Bitcoin's worst month has a real data basis: an average of minus 4.02%, a median of minus 4.72%, and 8 out of 13 years ending in the negative. However, the same data also shows that the pattern is weakening, with the last three Septembers all being positive since the market structure changed with the arrival of ETFs.
September 2026 has been practically flat so far, with Bitcoin moving from US$77,934 on September 3 to US$77,459 on September 14, following an August that saw a rise of approximately 25%.
The most interesting thing about this month is not its seasonal numbers, but the decoupling between price and public attention. Bitcoin is four to five times higher than its 2022 lows, while search interest in it is lower than it was back then.
The direction of September 2026 will ultimately be determined by the September 16 FOMC decision and the outcome of the September 15 CLARITY Act vote, rather than by the current month on the calendar. A more comprehensive guide on how to read market signals is discussed in how to analyze crypto.
Start with a Plan, Not a Calendar
If the calendar month cannot be used to predict market direction, the only things you can truly control are your entry strategy and position sizing. This is where dollar-cost averaging makes sense, as it removes the need to guess the perfect entry point—a task that even institutions with large research teams often fail to achieve. At Mobee, Bitcoin can be purchased directly with rupiah in small amounts, without needing to convert to dollars first or waiting to accumulate a large amount of capital.
For conditions like September 2026, which have been effectively sideways so far, there are tools specifically designed for such markets. Spot Grid places automatic buy and sell orders within a price range you define, allowing you to capitalize on fluctuations within that range without having to monitor your screen constantly. Meanwhile, for those who prefer to wait for the FOMC results and the CLARITY Act vote before increasing their positions, Flexi Earn ensures that your idle stablecoins continue to earn yield and remain available for withdrawal the moment the right opportunity arises.
FAQ
Disclaimer. All information in this article is for informational and educational purposes only and does not constitute investment recommendations or financial advice. Past performance does not guarantee future results, and seasonal data cannot be used as a basis for predicting price movements. All price data is point-in-time as of the article's drafting on September 14, 2026. Crypto assets are highly volatile and carry the risk of total loss. Conduct your own research and align your decisions with your individual risk profile.
