Bitcoin posts its best Q3 since 2017
Bitcoin closed the third quarter up around 43%, according to CoinGlass data cited by several market sources. Only Q3 2017 performed better, with a gain of close to 80.4%.
The performance is all the more unusual because summer has historically not been the most favorable period for BTC.
The third quarter ended in negative territory in 2014, 2015, 2016, 2019, 2022 and 2023. In 2024, Bitcoin gained only around 0.9%. In 2025, the increase remained close to 6%.
2026 has completely changed that pattern.
The quarter began near $58,000, following a particularly difficult first half of the year. Bitcoin lost around 22% in the first quarter, followed by another 14% in the second. By the end of September, its price had climbed back above $83,000.
BrefCrypto had already noted a monthly gain of close to 25% at the end of August, an unusual move in the middle of a bear market. September ultimately extended the trend rather than interrupting it.
Wall Street confirms the scale of the rebound. The Wall Street Journal calculates a quarterly gain of around 42%, well above the performance of major U.S. indexes. The S&P 500 rose only about 2% over the same period.
BTC therefore exited the quarter with momentum that looked very different from what was still being seen in June.
Ethereum performs even better
Bitcoin impressed. Ethereum did almost twice as well.
ETH ended Q3 up around 71%, after starting July near $1,570 and ending September close to $2,690. The gain exceeds the 66.5% recorded in the third quarter of 2025, which had been its previous record for this period of the year.
The reversal looks particularly dramatic when viewed against just a few months earlier.
Ethereum had lost around 29% in the first quarter, followed by another 25% in the second. In June, BrefCrypto even noted that ETH risked posting three consecutive quarters of losses for the first time in its history.
Three months later, the picture is almost completely reversed.
ETH not only avoided that sequence but also posted its best Q3 on record. CoinDesk likewise notes that this was its strongest quarter overall since the first quarter of 2021.
The performance also surpassed the famous 2020 “DeFi Summer,” when Ether gained around 59.5% in the third quarter.
The move accelerated during the second half of September. ETH rose from around $2,416 on September 17 to above $2,800 a few days later, before correcting slightly at the quarter’s close.
Ethereum’s relative strength is also clear against Bitcoin: the gap in quarterly performance is approaching 28 percentage points.
For an asset that had significantly underperformed BTC for much of the bear market, the shift is notable.
Q4 starts with a very high bar
The obvious question now is what October and the fourth quarter may bring.
Historically, this period has been much more favorable for Bitcoin. According to CoinGlass data cited by CoinDesk, Q4 has delivered an average gain of close to 77% since 2013, with a median of around 47.7%.
October has a reputation of its own. Bitcoin has historically posted an average return of nearly 20% during the month, hence the nickname “Uptober.”
The statistic obviously guarantees nothing for 2026.
The macroeconomic backdrop remains tense. U.S. bond yields rose sharply in the third quarter, and the 10-year Treasury yield moved above 5%. Reuters also highlights persistent market concerns surrounding interest rates, oil and U.S. monetary policy as September came to an end.
Bitcoin has not yet recovered its 2025 all-time high either. Despite an exceptional third quarter, Barron’s still placed it slightly in negative territory for 2026 as of the end of September.
The same applies to Ethereum: a quarter up 71% may look euphoric, but it came after two quarters of heavy losses.
That is precisely what makes this quarter-end so interesting.
Q3 does not prove that the bear market is definitively over. It does show, however, that the crypto market can produce a reversal of rarely observed magnitude during a period that has traditionally been relatively weak.
Bitcoin has just posted its second-best Q3. Ethereum has just broken its record. Q4 therefore begins with exceptional momentum, but also with expectations that will be much harder to meet.
