When the curtain eventually closes on the stock market in 2019, it's probably going to be one of the best years on record. Through this past weekend, the iconic Dow Jones Industrial Average had gained 20%, while the broad-based benchmark, the S&P 500, has galloped higher by 25%. To add some context to these figures, the 123-year-old Dow has risen by an average of 5.7% per year, while the S&P 500 has historically increased by 7% annually, inclusive of dividend reinvestment and when adjusted for inflation.

But no matter how well the stock market ends the year, it's important for investors to understand that there are virtually no "surefire investments" when it comes to Wall Street. Generally speaking, the closest thing to a surefire investment is an index fund, given that the market tends to rise in value over time. Nevertheless, all investments have risks, which pretty much negates the idea that any one stock is a surefire thing.

However, there is one stock with minimal risks that comes awfully close to being a surefire investment. Everyone say hello to robotic-assisted surgical system developer Intuitive Surgical (NASDAQ:ISRG).

A dollar sign emerging from a financial newspaper.

Image source: Getty Images.

Intuitive Surgical has a few risks...

Before I get into the many reasons Intuitive Surgical has a very high probability of long-term success, let's take a closer look at the relatively few risks currently sitting on the table.

Front and center would be the potential for major healthcare reform in the United States. Even though Intuitive Surgical has installed more than 5,400 of its da Vinci surgical systems around the world, most of them are located in the United States. When the Affordable Care Act (ACA) was officially implemented in 2013, there was genuine concern that hospitals (the core customer of Intuitive's surgical system) would pare back their spending given uncertainties associated with the ACA. With President Trump weakening the ACA during his nearly three years in office, there's always the potential for a new healthcare reform measure in the U.S. to take shape and disrupt hospital spending.

Another relatively obvious concern is that Intuitive Surgical will never have a monopoly on robotic-assisted surgical devices. There are always competitors that may try to undercut the da Vinci system on price (a range of $0.5 million to $2.5 million, depending on the model), or could offer a type of specialization that specifically goes after one or more of the strengths of the da Vinci surgical system.

Recessions are also a reasonable concern for Intuitive Surgical. It's not uncommon for high-growth companies with aggressive valuation multiples to sell off during recessions. Further, it wouldn't be out of the ordinary for patients to consider putting off elective procedures if economic growth slows. These are all factors that could weigh on Intuitive Surgical, and are what, ultimately, keep it from being a surefire investment.

But as I said, it's pretty darn close to surefire, and here are six reasons why.

A surgeon holding a one dollar bill with surgical forceps.

Image source: Getty Images.

... But it's about as surefire as they come for an individual stock

First, Intuitive Surgical has more installed surgical systems worldwide than all of its competitors combined -- and it's not even close. Being able to install more than 5,400 da Vinci systems worldwide means the company has built up quite the rapport with the medical community. What's more, by providing the training, servicing, and instruments for each procedure, Intuitive Surgical practically ensures that there's zero client turnover. In other words, once a hospital acquires a da Vinci system, they're liable to continue using that device for a very long time.

Second, consider that we don't get to choose when we get sick or what ailment(s) we develop. Whether the economy is booming or in recession, people are always in need of medical procedures, which provides a pretty steady level of procedural expectations for Intuitive Surgical.

A third reason this company is so impressive is because it's only going to get better with age. You see, in its earlier days, the sale of pricey da Vinci surgical systems comprised the majority of revenue. However, these systems tend to provide relatively low margins considering how complex and costly they are to build. The juiciest margins for the company are found in the instruments sold with each procedure, as well as the regular servicing needed to keep the systems functioning and up to date. As more da Vinci systems are installed, a growing percentage of revenue is now coming from higher-margin instruments and servicing. Therefore, as the company ages and its installed base grows, its operating margins should continue to improve.

Fourth, Intuitive Surgical is looking for ways to tear down cost barriers in order to push into more overseas markets. The 2017 introduction of the da Vinci X for closer to $1.1 million, as well as the ongoing retail of older or less costly models that can sell for well under $1 million, offer emerging markets an opportunity to buy into robotic-assisted technology without it (pardon the pun) costing an arm and a leg. 

A heart and blood pressure monitor in an operating room.

Image source: Getty Images.

Fifth, understand that Intuitive Surgical is really just scratching the surface of what its surgical systems are capable of. The da Vinci system is already a leader in urology and gynecology surgeries, but has an abundant runway to expand in thoracic, colorectal, and general soft tissue surgeries, where it currently holds only a small percentage of market share.

Sixth and finally, Intuitive Surgical is innovative and looking beyond just its dominant da Vinci platform. This past February, the company wound up gaining Food and Drug Administration approval for its robotic endoluminal system known as Ion, which uses a flexible biopsy needle to extract samples from a patient's lungs. It's also compatible within existing imaging technology. 

Intuitive Surgical is very profitable, it has a recession-resistant business model, and its lead over its peers is virtually insurmountable. That makes it the closest thing to a surefire investment you'll find among individual stocks.