Del. Code tit. 18 § 5103
Every person who is directly or indirectly the beneficial owner of more than 10 percent of any class of any equity security of a domestic stock insurer or who is a director or an officer of such insurer shall file with the Commissioner within 10 days after such person becomes such beneficial owner, director or officer a statement, in such form as the Commissioner may prescribe, of the amount of all equity securities of such insurer of which such person is the beneficial owner and, within 10 days after the close of each calendar month thereafter if there has been a change in such ownership during such month, shall file with the Commissioner a statement, in such form as the Commissioner may prescribe, indicating such person's ownership at the close of the calendar month and such changes in such person's ownership as have occurred during such calendar month.
18 Del. C. § 5103