31 CFR §363.210

A closed book period will be in effect for four business days prior to the date a marketable security interest and/or redemption payment is made. During the closed book period, you cannot change the registration of the security, change the payment destination of the proceeds, change the view or transaction rights, make transfers, or schedule, edit, or cancel a reinvestment. We will hold transactions requiring submission of a form for processing until the closed book period ends.