All payments on accounts of capital stock on any stock insurance company shall be made in lawful money or, subject to the limitations in the laws relating to insurance company investments, in securities publicly traded on a nationally recognized exchange (exclusive of stock issued in connection with an authorized merger or consolidation or as a stock dividend). Debt securities or preferred stock, in addition to being publicly traded on a nationally recognized exchange, must be rated as category 1 or 2 by the Securities Valuation Office of the National Association of Insurance Commissioners. No note or obligation given by a stockholder, whether secured by pledge or otherwise, shall be considered as a payment of any part of the capital stock.