Miért nem tudom felhasználni a készpénzemet, miután eladtam a készletemet egy készpénzes számlán?

In a Cash account, securities must be purchased using settled funds. When you sell a stock, the sale proceeds may not be fully settled immediately and therefore may not be available for all trading or withdrawal purposes until the settlement date.
If a client buys a security using unsettled funds and then sells that same security before the funds used to pay for the purchase have settled, this may be considered a free riding violation. Accounts that commit a free riding violation may be restricted for 90 calendar days, during which the account can only purchase securities using settled funds.