26 CFR § 1.818-7 — Denial of double deductions.

Section 818(f) provides that the same item may not be deducted more than once under subpart B, part I, subchapter L, chapter 1 of the Code (relating to the determination of taxable investment income), and more than once under subpart C, part I, subchapter L, chapter 1 of the Code (relating to the determination of gain or loss from operations).