September has been a mostly red month for the price of Bitcoin (BTC) and, consequently, for other digital assets as well.
The following chart, provided by the CoinGlass platform, shows BTC's monthly returns since 2013. It shows that there were 8 red Septembers (i.e., with negative returns) and only 4 green Septembers (with positive returns):
Monthly return of bitcoin (BTC) since 2013. Source: CoinGlass.
These statistical issues cause some fear in the Bitcoin and cryptocurrency investment community. One of the most cited reasons for this behavior is the seasonal effect: after the summer, financial markets generally show weakness, with investors adjusting portfolios, taking profits, or selling risky assets to meet year-end expenses and tax obligations.
In addition, there is a psychological bias: many traders anticipate weakness and act accordingly, reinforcing the pattern. Added to this is the lower liquidity typical of late summer, which amplifies volatility and declines.
Macroeconomic factors also play a role. September is typically a key month for central bank decisions, especially the US Federal Reserve, whose meetings generate uncertainty in the markets. Amid expectations of rate hikes or restrictive policies, investors tend to reduce their exposure to cryptoassets. While there's no guarantee that September will always be negative, the combination of seasonality, financial adjustments, and macroeconomic tensions has made this month a historically difficult time for Bitcoin
But in 2025, the situation could be different. The US Federal Reserve (FED) will announce interest rate changes on September 17. The majority expects the agency led by Jerome Powell to cut rates, which means an injection of liquidity into the financial markets.
If this happens, September 2025 is very likely to be a bullish month and a positive prelude to an even more bullish fourth quarter (perhaps with Bitcoin reaching new all-time highs).
It goes without saying that it's impossible to predict the future with complete certainty. But what is certain is that September 2025 will be a month of high volatility for Bitcoin and cryptocurrencies. So... fasten your seatbelts and enjoy the ride!
