Currently using SCB online trading platform to buy shares. Should I consider using CPFIS-OA to purchase shares/STI etf instead?

Not sure about SCB fees and structure.

but using CPF-IS, you need an agent bank, which practically acts as a custodian. So your shares will be held by the agent bank, and for that, they charge a fee for holding the shares, and for every transaction.

Pros - Under CPFIS rules, agent bank has to automatically appoint you as a proxy for any coporate action.

Back end work is relatively seamless for me. I trade like any cash platform. The agent bank do the work of transfering money to/from CPF.

Cons - CPF gives like 2.5% risk free. Shares and ETF cannot gaurantee.

There is limited amount which you can use in CPF OA, Think is 35% limit above the first $20k.

You cannot do share lending with CPF.

Even if you liquidate, the money flows back to CPF.

so, use CPFIS for only high conviction stocks you think can beat 2.5%

hope this helps.