Electricity and gas provider National Grid PLC (LSE:NG.) plummeted over 10% this morning after energy regulator Ofgem announced a £122 cut to the energy price cap.
The cap will be set at £1,568 for direct debit customers from July to the end of September, down from £1,690 currently, Ofgem said.
This determines how much suppliers can charge per unit of electricity or gas, with these set to cost 22.36p and 5.48p per kilowatt-hour respectively.
FTSE 100-listed National Grid shares bore the brunt of the announcement, though shares were already depressed following a deeply discounted rights issue on Thursday.
The stock was trading at a flat 900p at the time of writing.