JPMorgan Chase & Co. lowered its rating on bitcoin miner Riot Platforms Inc. to Neutral from Overweight, even as it nudged its 12-month price target to $15 from $14. Analyst research cited a 42% year-to-date surge that has left the stock ahead of bitcoin and sector peers, saying further gains will likely depend on Riot securing high-performance computing contracts or a renewed rally in the cryptocurrency. The bank issued a similar call on rival miner Iris Energy Ltd., cutting the stock to Neutral while lifting its target to $16 from $12. JPMorgan said both companies’ recent outperformance has stretched valuations, tempering the risk-reward profile despite progress diversifying revenue beyond traditional bitcoin mining.