Cal. Ins. Code § 1190

Any domestic incorporated insurer, which maintains in cash on hand or on deposit in a national or state bank, or in securities specified in Article 3 (commencing with Section 1170), an amount equal to its required minimum paid-in capital, may invest the remainder of its assets in the purchase of, or loans upon the securities set forth in this article. The investments are known as excess funds investments and are subject to the restrictions set forth in this article.