Panmure Liberum has downgraded Ceres Power Holdings PLC (LSE:CWR, OTC:CPWHF) from 'buy' to 'sell', arguing that the fuel cell technology company's extraordinary share price rally has outrun the realities of commercial scale-up, sending the shares down 5% to 689p. The broker raised its price target to 590p from 475p but said the stock, which has risen 244% year to date and 8x over the past 12 months to reach a market cap of £1.4 billion, now prices in manufacturing capacity growth that is unlikely to materialise at the pace the market assumes.