How do I know when a trading platform is legit and avoid investment scams?

When choosing a trading platform, make sure their website has been on the market at least 12 months. My best piece of advice would be looking at user reviews, and paying special attention to things like withdrawal limits or country/region restrictions. Many traders have invested, made a profit, and couldn't withdraw their money later because of some restriction. Contact your trading platform's support team and ask them these precise questions. You'll rarely find a popular trading platform that's not legit. Still, remember to do your research for country restrictions or withdrawal limits. Some of my suggestions would be platforms like Robinhood, WeBull, TradeStation, or Interactive Brokers.

Things to consider when choosing a platform:

1. Years of operation: This is really the first thing you probably should check for. Systems that have had more operational years should be considered. Novel systems would likely not know how to effectively manage under certain conditions. You wouldn't want to be caught in such circumstances.

2. Ease of money transfer: Making deposits and withdrawals should almost be hassle-free.

3. Good customer service: If you should have any complaints, there should be prompt response to your queries. Else, such systems might not be advisable to work with.

In my opinion, these might be the fundamental checklist to consider. You should do more research before investing your money in any platform.