In the case of Helvering, Commissioner of Internal Revenue v. Janney et ux., 1940, the United States Supreme Court was tasked with determining whether or not a taxpayer could deduct losses from their income tax return that were incurred as a result of selling securities at less than their cost in order to offset gains from other sales. The court ruled in favor of the Commissioner and held that such losses are deductible only if they are incurred in transactions entered into for profit. This decision clarified an important aspect of U.S. tax law: while taxpayers can use investment losses to reduce taxable income, this is only permissible when those investments were made with the intention to make a profit.

In the dissenting opinion for Helvering v. Janney, Justice McReynolds disagreed with the majority's interpretation of Section 22(a) and (b)(2) of the Revenue Act of 1928. He argued that these sections should not be read to include gifts in gross income unless they are made out of income or profits. According to him, Congress did not intend for all property transfers by gift to be included in gross income; rather, only those gifts derived from a donor's taxable earnings were meant to fall under this category. The justice contended that interpreting these provisions otherwise would lead to an unjust result where taxpayers could potentially face double taxation on their wealth: once when it is earned and again when it is given as a gift. This view was contrary to what he believed was Congress' intent behind enacting tax laws - ensuring fair distribution of tax burdens among citizens based on their ability-to-pay principle.