There's no minimum amount for SGD deposits, but we recommend to deposit at least $10 SGD to ensure your funds can be used to purchase securities efficiently. 

However, for USD deposits, there's a minimum deposit amount of $10,000 USD.

You have full discretion on how much and when you want to invest, including no minimum balance to maintain the account. You may also skip a month or two, resume, and withdraw whenever you wish — no charges or penalties.