Key legal question
Whether the shareholder interest in the real estate company was business assets or private assets for direct federal tax.
Extracted holding
The participation was business assets because the brothers conducted a side real-estate dealing activity through the partnership and controlled the company.
Extracted reasoning
The court relied on the overall pattern: formation of the partnership, acquisition of the company, financing with external funds, active combined use of work and capital, and the later transfer of properties as part of a broader trading activity.