Publication 598
taxmap/pubs/p598-009.htm#en_us_publink100067580An organization that owns S corporation stock must take into
account its share of the S corporation's income, deductions, or losses in
figuring unrelated business taxable income, regardless of the actual source or
nature of the income, deductions, and losses. For example, the organization's
share of the S corporation's interest and dividend income will be taxable, even
though interest and dividends are normally excluded from unrelated business
taxable income. The organization must also take into account its gain or loss on
the sale or other disposition of the S corporation stock in figuring unrelated
business taxable income.