Bitcoin is up about 7% in September, following a 25% gain in August. Since 2013, every positive August has been followed by a negative September. A positive close this month would break this historical streak and mark Bitcoin's first positive quarter since Q3 2025, with a more than 40% increase. However, rising bond yields, oil prices above $90 a barrel, and upcoming November events like the Anthropic IPO and U.S. midterm elections could challenge its Q4 momentum.