When money is lent to a partnership or S-corporation acting as a pass-through entity (essentially a business that is designed to reduce the effects of double taxation) by that entity’s owner, the interest income on that loan to the portfolio income can qualify as passive income. As the IRS language reads: "Certain self-charged interest income or deductions may be treated as passive activity gross income or passive activity deductions if the loan proceeds are used in a passive activity."
Risk: The tricky part is choosing the right stocks. Graves warns that too many novices jump into the market without thoroughly investigating the company issuing the stock. “You’ve got to investigate each company’s website and be comfortable with their financial statements,” Graves says. “You should spend two to three weeks investigating each company.”

In equity valuation, residual income represents an economic earnings stream and valuation method for estimating the intrinsic value of a company's common stock. The residual income valuation model values a company as the sum of book value and the present value of expected future residual income. Residual income attempts to measure economic profit, which is the profit remaining after the deduction of opportunity costs for all sources of capital.