Can you use money from your CPF to do index investing?
Yes!

If you are using your money from your CPF Ordinary Account (OA), you can open a CPF Investment Account with any one of the three CPFIS agent banks :

1. DBS Bank Ltd (DBS)
2. Oversea-Chinese Banking Corporation Ltd (OCBC)
3. United Overseas Bank Ltd (UOB)

Any amount in your CPF ordinary account (not including the first S$20,000) can be invested into Exchange-Traded Funds (ETF).
Important Things to Take Note
1. Transaction Charges – Check with individual banks for latest rates
2. Service Charges – S$2 service charge, per counter, every quarter
These two will quickly increase your cost if you’re investing a small sum monthly!