[Analysis: Bitcoin and S&P 500 Correlation Strengthens Over the Past Decade] CryptoQuant analyst Darkfost points out that, calculated over a 90-day rolling window, the cumulative Z-score of the correlation between BTC returns and S&P 500 returns has broken through zero for the first time since 2015, reaching 98.5. A score above 0 indicates a higher-than-usual correlation, while a score below 0 indicates a lower correlation; the cumulative Z-score summarizes the deviation to show a trend. Darkfost states that this trend has been clearly upward since the low point, and this breakout is symbolic, meaning that BTC and the stock market are increasingly moving in tandem. However, Darkfost also observes that the recent upward momentum of this correlation is slowing. The rate of change measuring the short-term (90-day) correlation has fallen from its recent high to +6.3%. In other words, while the correlation remains above average, it is no longer strengthening as rapidly as before.