Treasury Regulation § 20.2031-8 (b) 1 addresses the valuation of mutual funds. It states “If there is no public redemption price quoted by the company for the applicable valuation date (e.g., the valuation date is a Saturday, Sunday, or holiday), the fair market value of the mutual fund share is the last public redemption price quoted by the company for the first day preceding the applicable valuation date for which there is a quotation.”