** Brokerage J.P.Morgan downgrades IREN IREN.O to "underweight" from "neutral" and CleanSpark CLSK.O to "neutral" from "overweight"
** Shares of bitcoin miner IREN down 4.6% at $44.2, while per CLSK falls 4.5% to $13.07 premarket
** Riot Platforms RIOT.O shares offer the best value relative to other operators, upgrade to "overweight" from "neutral", raises PT to $19 from $15 - Brokerage
** Riot Platforms shares up 5% to $17.6
** JPM says IREN already prices in a colocation deal of over 1 GW at the Sweetwater facility; while record-scale, it offers more downside than upside at current levels
** CLSK shares fully price in the company"s recent expansion, and investors need more clarity on high-performance computing (HPC) plans to drive further gains - JPM
** As of last close, RIOT up about 64% YTD, CLSK up about 48% and IREN share more than quadrupled in value