For SGD deposits, there is no minimum deposit amount required.
However, for USD deposits, there is a minimum deposit amount of $10,000 USD per deposit.
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. All without incurring charges or penalties.
*Note : For Income portfolio, there is a minimum balance required of SGD10,000.