Analysis shows that Bitcoin and Ethereum have the strongest correlation with the DAX index. The correlation coefficient matrix of ETH is 0.46, which means that while there is a certain correlation, it is not strong. Bitcoin, on the other hand, has a correlation coefficient matrix of 0.85, indicating that its price is quite consistent with the movements of the DAX index. Similarly, BTC also has significant correlations with other stock market indices, with correlations of 0.7, 0.68, and 0.69 with the Russell 2000 index, S&P 500 index, and Dow Jones Industrial Average, respectively. In contrast, Ethereum is almost completely independent of these indices, with its correlation coefficient matrix being very close to zero with these indices.