Why is that Nikkei STI ETF can be bought without setting up a CDP account while SPDR STI ETF requires a CDP account?

Hey Anon, I'm assuming the Nikko STI ETF that you're referring to is under DBS InvestSaver. In this case, the ETFs are held under DBS (custodian account) which is why you do not need a CDP account.

Also, depending on which broker you use, you may or may not need a CDP account, regardless whether it's Nikko STI ETF or SPDR STI ETF. The difference is if it's CDP, the shares are legally held under your name while for custodian, it's held under the brokerage firm.

Check out Seedly's article to understand better https://blog.seedly.sg/the-ultimate-cheatsheet-... ​​​