15 ILCS 520/15

(a) A financial institution approved as a State depository shall cease to be an approved depository financial institution, and shall be disqualified by the State Treasurer: (1) Upon its failure to post a suitable bond or deposit assets or securities with the State Treasurer; (2) Upon its failure or refusal to pay over public moneys or any part thereof; (3) Upon its becoming insolvent or bankrupt, or being placed in the hands of a receiver; or (4) Upon a showing of unsatisfactory financial condition through a report made to, or an examination made by any regulatory or licensing body. (b) No approved depository shall be disqualified by the State Treasurer solely by reason of its acquisition by another institution, unless the acquiring institution does not meet the criteria established by the State Treasurer. (c) An approved depository may be disqualified by the State Treasurer, in his or her sole discretion, for violating the terms of the deposit agreement or any contract or agreement with the State Treasurer.