With most customers on fixed tariffs this is a major concern for many energy suppliers.
Ones to watch —>
Centrica owner of British Gas - 💡 Centrica plc 🔥 (£CNA)
SSE - SSE plc 🏴 ⚡ - SSE - Share Chat - #7 by bhav
There must be some wholesale suppliers who are winning from this but I’ll leave hat for someone else with more knowledge to post.