Features vary by brokerage app, of course, but many apps build in additional controls for withdrawals besides just log in once and do everything"

• Even if you are logged in, putting in a transaction may require re-verifying the 2FA

• Even if a fraudulent sell order is somehow initiated, transfers of funds out are often limited to pre-validated accounts. If a fraudulent actor tried to withdraw to a different account , there would often be a verification step which would involve further 2FA

• While it might be annoying to have to wait for transactions to clear, that's actually a protection for you. If you start getting random 2FA requests that you didn't initiate, just contact the broker and let them know, and they will probably freeze the whole thing. They can probably unwind transactions due to fraud, but only if you contact them before they clear.

I, personally, am much more comfortable with brokerage apps on my phone than storing a credit card on my phone, because those can create transactions with NFC, while there is a lot more security on the brokerage apps.