In the cryptocurrency world, if you've made quite a bit of money and want to withdraw, will the bank ask about the source of the funds?

Let's assume you've earned one hundred million dollars.
If you sell a lot of coins into the marketplace daily and don't withdraw, reaching five million, the bank will call you and visit your home, asking you to buy financial products, trust funds, insurance, or upgrade to VIP gold cards.
If you sell coins to the marketplace, you will definitely encounter money laundering, third-level money laundering—though not much—and your account may be frozen for three days. However, with such a large amount in your account, it might be frozen for six months.
If it's second-level money laundering, the freeze could last six months or even result in confiscation. If the amount isn't too large, you might pay a 10% compensation to resolve it. But if it's too much, authorities might take drastic measures, such as forcing you to go through a sewing machine or banning internet access, card opening, and loans for five years.
If you buy coins at a very low price or sell coins at a significantly higher market price—say the market price is 7 yuan, and you sell at 7.5 yuan—that indicates knowledge of the discrepancy, which is considered guilty.
If you receive first-level money laundering, then there's nothing much to say—it's a minimum of three years in prison. The charge will definitely be concealment of criminal proceeds.
If you're selling coins, definitely do not go to the marketplace. Take my advice: be cautious and avoid platforms altogether. Never engage in offline cash transactions, as cash dealings are highly likely to involve money laundering, and your personal safety could be at risk. Don't put yourself in danger.
When you make money, I’ll tell you how to exit safely. Find someone you trust. Usually, they will pay you first, then you transfer coins, and only after verifying the funds—if the capital hasn't been in your account for more than three days—and avoiding frequent large transactions.
You don't need to sell all your earnings at once, just sell gradually. For example, if you want to cash out 10 million, you can use Alipay and withdraw about 200,000 yuan daily. There's no need to rush; rushing can lead to problems.
You probably don't need to use a bank card for everything.
Many people say they convert to Hong Kong dollars or other currencies, but that process is very complicated.
If you sell only a small amount, the bank usually won't ask questions.
But if your account receives large sums daily, it might be flagged and frozen at the counter, so you'll need to go to the bank branch to withdraw cash.
All of this is to prevent telecom fraud and to stop your card from being lent out.
If your background is clean—no involvement in drugs or black organizations—and you make money from selling coins, your funds are clean, the bank won't ask many questions. Rest assured.
If you have any history, then they will investigate very thoroughly.