17 CFR 300.501: Claim for cash.

(a) Where a SIPC member (“Debtor”) held securities in an account for a customer, the customer has a “claim for cash” with respect to any authorized securities sale:

(1) If the Debtor has sent written confirmation to the customer that the securities in question have been sold for or purchased from the customer's account; or

(2) Whether or not such a written confirmation has been sent, if the securities in question have become the subject of a completed or executory contract for sale for or purchase from the account.

(b) Where the Debtor held cash in an account for a customer, the customer has a “claim for cash”, notwithstanding the fact that the customer has ordered securities purchased for the account, unless:

(1) The Debtor has sent written confirmation to the customer that the securities in question have been purchased for or sold to the customer's account; or

(2) Whether or not such a written confirmation has been sent, if the securities in question have become the subject of a completed or executory contract for purchase for or sale to the account.