In financial terms, passive income describes money that a one-time investment continually generates, without requiring the investor to monitor or adjust his or her holdings. The passive investing strategies below warrant a closer look.

1. Real Estate

Despite fluctuations over the recent years, real estate persists as a preferred choice for investors looking to generate long-term returns. Specifically, rental properties can furnish apartment owners with a regular income source. The investor can easily acquire a property for a 20% down payment, then install reliable tenants who keep the money flowing.

Those who don't want to manage rental properties can look to real estate investment trusts (REITs) instead. REITs pay out 90% of their taxable income as dividends to investors. On the downside, dividends are taxed as ordinary income, which may be problematic for investors in higher tax brackets.

Real estate crowdfunding presents a middle-ground solution. Investors have their choice of equity or debt investments in both commercial and residential properties. Unlike REITs, crowdfunding lets investors enjoy the tax advantages of direct ownership—including the depreciation deduction, without the added responsibilities of property ownership.

2. Peer-to-Peer Lending

Although the peer-to-peer lending (P2P) industry (aka crowdfunding) is just over a decade old, it has grown by leaps and bounds. It is defined as the act of directly lending money to a person or a business entity, where lenders and the borrowers are connected via online platforms such as Prosper and Lending Club. Returns typically range from 7% to 12%, and there's very little the investor must do after initially funding the loan.

P2P programs generally have fewer barriers to entry than other types of investments. For example, investors can fund loans with investments as small as $25. While Title III of the Jumpstart Our Business Startups (JOBS) Act allows both accredited and non-accredited investors to invest through crowdfunding, each P2P platform has its own set of participation requirements.

3. Dividend Stocks

Dividend stocks are one of the simplest ways for investors to create passive income. As public companies generate profits, a portion of those earnings are siphoned off and funneled back to investors in the form of dividends. Investors can decide to pocket the cash or reinvest the money in additional shares.

Dividend yields can vary significantly from one company to the next, and they can also fluctuate from year to year. Investors unsure about which dividend-paying stocks to choose should stick to the ones that fit the dividend aristocrat label, which means the company has at least a 25-year track record of paying out substantial dividends.

4. Index Funds

Index funds are mutual funds linked to a particular market index. These funds aim to mirror the performance of the underlying index they track and are passively managed. Therefore, their underlying securities don't change unless the composition of the index shifts. For investors, this translates to lower management costs and lower turnover rates, which makes them more tax-efficient vehicles than many other investments.

The Bottom Line

Passive income investments can greatly simplify an investor's life. The four options above represent differing levels of diversification and risk. As with any investment, it's important to weigh the anticipated returns associated with passive income opportunities against potential losses.