Another important distinction is that, under the law, accounts can be either a demand deposit account (typical bank accounts like checking or savings) or a brok

Another important distinction is that, under the law, accounts can be either a demand deposit account (typical bank accounts like checking or savings) or a brokerage account. They can't be both. As the name suggests, Financial institutions _must_ allow customers to withdrawal some or all of the funds in a demand deposit account at any time, without penalty and without requiring prior notice. Because of the time it takes for the settlement of securities transactions brokerage accounts don't have the same obligations. If you put $100 in a traditional checking account and you need it today you have the right to access it immediately (assuming the bank is open). If you put $100 in a Robinhood account and you need it today you might have to wait three. When Robinhood calls a product a "checking" account that fundamental concept of immediate access to your money is implied to consumers but looking at their site there are all kinds of restrictions around dollar amount and frequency of withdrawals.