The total hashrate of the U.S.-listed bitcoin (BTC) miners tracked by JPMorgan (JPM) has almost doubled from a year ago and now accounts for about 29% of the global network, the bank said in a report on Tuesday.

The combined hashrate of the 14 companies «has increased ~95% y/y to 244 EH/s, versus a 45% increase in the network hashrate,» analysts Reginald Smith and Charles Pearce wrote.

The network hashrate is a proxy for competition in the industry and mining difficulty. The Bitcoin network hashrate has risen about 6% so far this month, and has climbed 45% in the last 12 months, the report said.

«Average bitcoin price also declined modestly from January, pressuring mining economics,» the authors wrote.

The hashprice, a measure of daily mining profitability, dropped 13% from the end of January, as the hashrate rose and the bitcoin price fell, JPMorgan said.

The bank estimated that miners earned around $53,600 in daily block rewards this month, 6% lower than in January.

The total market cap of the bitcoin mining stocks in the bank’s coverage was 1% lower than the month previous, the report added.

IREN (IREN) outperformed in the first two weeks of February with a 27% gain, the bank noted. Greenidge Generation (GREE) underperformed with a 20% drop.

In a Monday report, broker Bernstein said U.S. bitcoin mining stocks were increasing their share of the network hashrate.

Read more: U.S.-Listed Bitcoin Miners Are Growing Their Share of the Network Hashrate: Bernstein