What is the best bank account for investing in US stock and cryptocurrency? In terms of forex, zero fees, fast transfer process etc

Are you looking for a brokerage or a bank account?

From the way your question is phrased, I would assume brokerage.

Let's start with stocks. Stockswise, if you're looking at US stocks mainly, I would say Tiger and Moomoo are good options to start with. Easy to create, cheap commissions, fast deposit and withdrawl (no fees too), decent forex. If you're going to trade frequently, or looking to trade options, you might want to consider IBKR instead as they have more support for such strategies.

For crypto, I wouldn't recommend stock brokers to buy crypto with. Mainly because most stock brokers (e.g., US Robinhood), don't allow transfer of crypto out of their broker. As such, your crypto is essentially not yours as you don't have full control over it. I would recommend dedicated crypto exchanges instead.

If you're going to buy and hold, BinanceSG and Gemini are decent. They both have fee structures that are decent and support using SGD to purchase crypto. Gemini does have a slightly cheaper commission on their activetrader mode (0.35%) while BinanceSG is a little higher (0.6%).

If you're looking to trade crypto instead, Binance(.com) is definitely the superior option. 0.1% commissions and a wide selection of crypto, plus various products to earn more on your own crypto, Binance(.com) is hard to beat.

Hope this helps, feel free to ask in the comments if you need any clarification.​​​