To the extent provided by the Secretary, subsection (a) shall not apply to income or gain attributable to any asset not held for portfolio investment on behalf of third party investors.
Except as provided in this paragraph or paragraph (4), the term “applicable partnership interest” means any interest in a partnership which, directly or indirectly, is transferred to (or is held by) the taxpayer in connection with the performance of substantial services by the taxpayer, or any other related person, in any applicable trade or business. The previous sentence shall not apply to an interest held by a person who is employed by another entity that is conducting a trade or business (other than an applicable trade or business) and only provides services to such other entity.
The term “specified asset” means securities (as defined in section 475(c)(2) without regard to the last sentence thereof), commodities (as defined in section 475(e)(2)), real estate held for rental or investment, cash or cash equivalents, options or derivative contracts with respect to any of the foregoing, and an interest in a partnership to the extent of the partnership’s proportionate interest in any of the foregoing.
The Secretary shall require such reporting (at the time and in the manner prescribed by the Secretary) as is necessary to carry out the purposes of this section.
The Secretary shall issue such regulations or other guidance as is necessary or appropriate to carry out the purposes of this section [2]