Bitcoin's mining hash rate hit a record high of 544 exahashes per second (EH/s) on Christmas day, putting pressure on miners as profitability slumps. The network hash rate has more than doubled this year, increasing 130% since January. However, hash price, a measure of profitability, has fallen 34% since its 2023 high of $0.136/TH/s/day on Dec. 17. High hash rates make it harder for miners to secure the next block, and profitability often drops when demand is low, leading to lower transaction fees.