Ether-linked stocks jump as cryptocurrency hits seven-month high
** Shares of ether-linked companies rise premarket** Cryptocurrency ether hits seven-month high; last up 1.64% at $3,887.13** Blockchain-focused companies Gamesquare Holdings up 6.2%, BTCS rises 7.7%, Bitmine Immersion Technologies up 4.1%** Sharplink Gaming jumps 8.2%, while Bit Digital rises 5.4%** iShares Ethereum Trust ETF jumps 7.1%