The late, great entertainer Prince said in one of his hit songs that "forever is a mighty long time." Truer words have never been spoken.

Many investors don't think in terms of mighty long times. But they should. The longer your investing horizon, the greater your chances are of generating huge gains.

Some stocks are especially well-suited for long-term investors. Here are three rock-solid stocks that you can buy and hold forever.

Infinity symbol formed by $100 bills

Image source: Getty Images.

Disney

A few years ago, some investors were worried that cord-cutting could turn Disney (DIS 0.16%) into a has-been. Those concerns certainly appear to be overblown in retrospect. The entertainment giant now reigns as a leader in streaming TV with Disney+, ESPN+, and Hulu.

I think that Disney's impressive streaming success underscores two reasons why the stock remains one to buy and hold for the long run. First, the value of the company's existing content library and capability to generate new content should never be underestimated. Second, Disney will always expand into new arenas to reach a wider audience. And when it does, the company nearly always does it right.

While Disney is a great long-term pick, it appears to be poised to win over the short term as well. More Disney theme parks are reopening as pandemic fears subside. The company's delayed movie debuts will be shown in theaters that could actually have large audiences in them in the not-too-distant future. Even Disney's cruise line will be back in business not too far down the road.

The future of entertainment could change a lot over the coming decades. Augmented and virtual reality might take off in a massive way. Maybe one day you'll even be able to participate in the movies that you watch. Whatever happens, though, it's a good bet that Disney will be front-and-center.

Intuitive Surgical

Robotic surgical systems pioneer Intuitive Surgical (ISRG -1.69%) ranks as one of my favorite healthcare stocks to buy and hold. Its financial position is exceptionally strong. It's delivered tremendous returns over the last two decades. And it has plenty of opportunities for future growth.

To be sure, Intuitive Surgical faced some challenges with the COVID-19 pandemic. Non-urgent surgeries were delayed, resulting in Intuitive's consumable sales faltering. However, those were only temporary issues. The widespread availability of vaccines should help put the COVID-19 challenges to rest.

In 2020, over 1.2 million procedures were performed using Intuitive Surgical's surgical robots. The company estimates that around 6 million procedures are done each year for which its technology already has regulatory clearances. 

That's just the tip of the iceberg for Intuitive's growth potential, though. Roughly 20 million soft-tissue surgeries are performed annually. As the company continues to innovate and win additional clearances, it will be able to target this larger market. Robotic surgery is still only in its early innings. Intuitive Surgical should be in a great position to dominate this expanding market for a long time to come.

Mastercard

Cash continues to go by the wayside. Mastercard (MA 0.15%) stands out as one of the best stocks to profit from this trend.

The company, along with Visa, enjoys a duopoly in processing credit card payments. This gives Mastercard a strong revenue stream. It also gives the company a formidable moat. Those are two attributes that make for great long-term buy-and-hold stocks.

Mastercard is expanding its payment processing infrastructure beyond just credit cards. It recently acquired the corporate services business of European payment technology leader Nets. This deal gives Mastercard a clearing and settlement infrastructure for account-to-account digital payments. The company is also introducing new contactless solutions that use its payment processing capabilities for credit cards without requiring physical cards.

E-commerce will continue to gain momentum in the coming years. So will contactless digital payments in brick-and-mortar locations. Mastercard is poised to win in both areas. Like Disney and Intuitive Surgical, this fintech stock is one you can hold forever -- or at least for a mighty long time.