#BitcoinHashRateSurge Review of historical data indicates that mining activity increased between reward reduction events. However, due to its exponential growth, identifying a clear cycle is challenging - we have done some work on this here. Since hash rate tends to be a volatile figure, using trend deviation on historical data provides more accurate results than purely qualitative methods. A key problem, however, is that most trend lines incorporate forward-looking information, meaning that the trend line we see today would have appeared differently in the past. Therefore, the most reliable method is to calculate a trend line based on out-of-sample data, which is not influenced by future developments.