Bitcoin is up about 7% in September after August's 25% gain, and with two calendar days left a positive close would break a pattern that has held since 2013, when every prior positive August was followed by a negative September. It would deliver three straight monthly gains from July through September and leave the third quarter up more than 40%, its first positive quarter since Q3 2025. The fourth quarter has historically been the strongest, with CoinGlass putting the average gain near 77%, though the macro backdrop is doing none of the usual work: the 10-year yield sits above 5.2% and the MOVE index of bond volatility is above 100, near year-to-date highs.