According to CoinDesk, the Bitcoin network hashrate has returned to pre-halving levels, with U.S.-listed miners' share of the network hashrate increasing for the fifth consecutive month to a new record. The hashrate, which measures the total combined computational power used to mine and process transactions on a proof-of-work blockchain, has risen 4% month-to-date. This increase in hashrate indicates heightened competition in the mining industry.JPMorgan noted in a research report that the hashprice, a measure of miners' daily profitability, has fallen 2% this month and is more than 50% below pre-halving levels. This decline, coupled with seasonal trends, could limit hashrate growth in the near term. Analysts Reginald Smith and Charles Pearce highlighted that U.S.-listed miners' share of the network hashrate reached 26.7%, the highest level on record.The total market capitalization of the fourteen U.S.-listed bitcoin miners tracked by JPMorgan fell 3% from the end of August to just under $20 billion. Among these miners, Hut 8 (HUT) outperformed with an 11% gain, while CleanSpark (CLSK) underperformed, declining 12%. The group of publicly listed U.S. miners currently trades just under two times their proportional share of the four-year block reward opportunity, compared to an average of 1.6 times since January 2022.Rival Wall Street Bank Jefferies issued a cautionary note, suggesting that bitcoin miners could face another challenging month in September. This follows a report indicating that Bitcoin mining was significantly less profitable in August.