Your questions about SoFi Hong Kong are answered here

Your minimum contribution to start investing is US$100. You may reference the following transaction amounts below.

Minimum Contribution: US$100 Min Monthly Recurring (Optional): HK$100 Min Subsequent Deposit: US$10 Min Withdrawal: US$10*

*If your asset balance is below US$100, your min. withdrawal amount is your asset balance. If you decide to withdraw from Auto Invest, your funds will be transferred to your Direct Invest account.