Wis. Stat. § 221.0525: Shares of stock, when not transferable.

The shares of stock of a bank are personal property. The bank shall transfer the shares on the books of the bank in such manner as the bylaws may direct. A transfer of capital stock is not valid while the bank is under notice to make good the impairment of its capital, as provided in s. 220.07, until the impairment is made good. A transfer of stock shall be certified by an officer of the bank to the division within 3 days after the transfer, if the transfer is of at least 5 percent of the outstanding shares or affects the holdings of the owner of record or beneficial owner of at least 5 percent of the outstanding shares. A person who fails to comply with this certification requirement may be fined not more than $100.