Bitcoin investors may be entering their toughest period of the year. Historically, August and September are among the weakest performing months for Bitcoin (BTC). Prices have fallen in these two months in 8 of the last 12 years, implying a probability of decline of approximately 67%. Data shows that Bitcoin generally performs poorly in the third quarters (July–September). Specifically, it experienced significant declines, such as -2.85% in the third quarter of 2022, -21.51% in 2019, -2.85% in 2018, and -13.54% in 2014. Bitcoin's average third-quarter return was only 1.46%, while the median return was -1.46%. On the other hand, the first quarter of the year is generally positive for Bitcoin. For example, strong Q1 returns of 68.68% were recorded in 2023, 102.93% in 2021, and 11.89% in 2019. August has been the month with the most negative returns over the last 12 years, with notable declines such as -13.88% in 2022, -17.27% in 2014, and -9.05% in 2013. September is historically the weakest month, with declines of -24.92% in 2014, -13.38% in 2019, and -3.59% in 2022. The average September return remains in negative territory. Similar to Bitcoin, Ethereum (ETH) also performs poorly in third quarters. For example, while ETH gained +25.01% in Q3 2022, it experienced declines of -18.9% in 2021, -38.82% in 2019, and -37.28% in 2018. Ethereum's Q3 average was 5.72%, but its median was 3.02%, suggesting rather limited earning potential. *This is not investment advice.