“Unless otherwise agreed in writing, all money which is now or may later be credited to the Account (including all interest) is our joint property with the right of survivorship.”

“…where two or more holders of a joint account all sign an account opening document (or separately sign identical documents) which, on their true construction, declare or set out their respective beneficial interests in [entitlement to] the property constituted by the account (loosely, the money in the account), then those are the beneficial interests of the account holders, pending any subsequent variation of them [barring change in the arrangements] by agreement or otherwise, and an examination of the subjective intentions of the account holders, or of those of them who place money in the joint account, is neither relevant nor permissible.”