CA Pub Res Code Section 9530

(a)

“Surplus moneys,” as determined pursuant to Section 9529, shall be invested exclusively in bonds or interest-bearing notes or obligations of the United States, or those for which the faith and credit of the United States are pledged for the payment of principal and interest.

(b)

Interest earned and other increment derived from any investment under this section shall be credited to the surplus money account for investment under this section.