If the market value of assets and securities of an insurer held on deposit in this state, or in another state under custodial arrangements authorized by AS 21.24.040(c), falls below the amount required under this title, the insurer shall promptly deposit other or additional assets or securities eligible for deposit under this chapter and in an amount sufficient to cure the deficiency. If the insurer fails to cure the deficiency within 20 days after receipt of notice by registered mail from the director, the director shall immediately revoke the insurer's certificate of authority.