It is worth it to top up $7,000 for SA to save $800 in income tax? Thinking that I need to generate at least 11.5% in returns if i put the $7,000 into the stock market. What would you do? TIA!?

Look like you are in the 12% income tax bracket, top up $7000 to your own SA and $7000 wife SA and then 15300 SRS. CPF OA can use to buy unit trust getting about 8% return. Why pay so much income tax?

Personally, perference is invest. reason being 1) I am already contribuing through salary every month, 2) CPF is not withdrawable until retirement. even during covid it was not allowed for anyone to withdraw. therefore I am of the opinion that there is no need to lock in liquid cash for that long.

but in your case, you are getting $800 on $7000, add the further 4% interest, you are getting like 14% on $7000. very good deal.

another case where people might consider to top up SA is if their rainy day funds etc all taken care of, extra cash they don't want to invest in public markets, so top up is a good option.