Unless the income, gains, or both, arise from transactions in the regular course of the taxpayer’s trade or business carried on in this state, or unless the acquisition, management, and disposition of intangible personal property constitutes a trade or business carried on in this state, or unless the income, gains, or both, arise from gaming activity carried on in this state, income of nonresidents derived from land contracts, mortgages, stocks, bonds, or other intangible personal property, or from the sale of intangible personal property, may not be taxed.