Oh, good catch. The IRS instructions on valuing charitable gifts of stock supports your interpretation: https://www.irs.gov/publications/p561#idm1405011579728

Oh, good catch. The IRS instructions on valuing charitable gifts of stock supports your interpretation: https://www.irs.gov/publications/p561#idm140501157972816 https://www.irs.gov/publications/p561#idm140501157972816 > determining the value of large blocks of stock usually requires the help of experts specializing in underwriting large quantities of securities, or in trading in the securities of the industry of which the particular company is a part i.e. it's not just "(market price) x (number of shares)" Although when I looked at the article it seems that they do not actually claim that he was able to deduct $500 million. They strongly imply it by saying that "his tax savings were pegged to the shares’ all-time high" but in terms of the actual deduction they just write that he "likely saved millions of dollars" which is accurate.