In a cash account, how much must a customer deposit when purchasing stock?

In a cash account, the customer must deposit the full value of the stock they wish to purchase. This requirement is essential to ensure that the funds are available to cover the entire transaction before the purchase can be executed. The correct answer indicates that the full value of the stock is considered, with the exception of any premiums from written options, which can be deducted from the total amount required.

This reflects the principles of a cash account where transactions must be fully paid for in cash without borrowing against margin. In this context, it's important to acknowledge that using margin or an alternative financing option would involve different regulations and requirements, which aren’t applicable to a traditional cash account. Thus, in a cash account setting, it’s crucial to have sufficient funds to cover the total cost of the stock purchase upfront.