Moomoo is heavily regulated and its clients are insured, so we can say with confidence that yes, moomoo is safe. Like most other legitimate investment platforms, moomoo is heavily regulated. Both the U.S. Securities and Exchange Commission (SEC) and the Financial Industry Regulatory Authority (FINRA).
Funds placed on hold are not available to withdraw until the hold is cleared from your account. Funds may be placed on hold for the following: Open order being processed. Pending withdrawal requests.