If I have 100k in us stock market. when I want to withdraw do I need to declare anything with lhdn? bank will flag the transaction? how to prove it is capital gains?

You need to declare to lhdn you have overseas bank/brokerage account. If you don't declare, it shows that you are trying to hide stuff as most brokerage participate in CRS so basically lhdn already know you got overseas bank/brokerage account without you needing declare.

Your brokerage will have monthly statement, activity statement. You can just download that as proof.

May I know what is the process in declaring that I have oversea brokerage account?

During annual filling up of income tax form, there is a checkbox to delcare you got overseas bank/brokerage account.

This post has been edited by Ramjade: Aug 9 2021, 11:02 PM