Source: https://www.ema.gov.sg/Residential_Electricity_Tariffs.aspx
As of 15 Oct 2021, only 10 electricity retailers companies left which you can switch out from SP Group for your house electricity. Ohm energy & iSwitch had just announced they will exit and all customers signed under the company will be transfer back to SP Group wef 20 Oct & 12 Nov respectively (Link). Due to the recent spike in electricity rates, expecting more electricity retailer to exit soon (High potential are Best Electricity as they seem to stop new signup and Diamond Electric as the only plan they have is 0% discount).
To sign up for FIXED or DISCOUNT plan? My recommendation is to sign up for FIXED plan. If you need statistics data, please refer to my old post here. I believe those on Discount plan will tell you how much higher they are paying since the tariff rate have been revised...