The effective interest rate for September 2020 Singapore Savings Bonds (SBOCT20 GX20100N) is 0.90% if you held it for 10 years. The interest rate has recovered slightly as compared to 0.88% in August. The COVID-19 pandemic that started in March 2020 had caused the interest rates to fall dramatically across fixed deposits and savings accounts.
The minimum amount you can purchase is S$500. If you decide to hold and sell the current issue (SBOCT20 GX20100N) after 1 year, the effective interest rate is 0.26%.