12 CFR § 150.310
What if the FDIC does not insure the deposits?
November 10, 2020
If the FDIC does not insure the entire amount of a self deposit, you must set aside collateral as security. If the FDIC does not insure the entire amount of an affiliate deposit, you or your affiliate must set aside collateral as security. The market value of the collateral must at all times equal or exceed the amount of the uninsured fiduciary funds. You must place the collateral under the control of appropriate fiduciary officers and employees.