The S&P 500 is in full swing right now, having entered the third year of a bull market. But one thing history shows is that it’s just a matter of time before the stock market crashes again. It’s an inevitable part of investing.

To be clear, a correction is a drop of 10% from recent highs, while a crash is a decline of 20% or more. Neither is the end of the world. In fact, the second lesson from history is that the market has always eventually bounced back to scale new highs.

Therefore, I’d see a crash as a great time to do a bit of discounted shopping. And this is the one world-class S&P 500 share I’d like to buy more of during a market meltdown.

Surgical robots

I’m thinking about Intuitive Surgical (NASDAQ: ISRG), the pioneer in robotic-assisted surgery. Its flagship da Vinci system helps surgeons perform minimally invasive procedures, which often lead to faster recovery times and shorter hospital stays.

Last year, 2.2m procedures were performed worldwide using da Vinci machines. And over 15m have now been performed over the past two decades.

In Q3, worldwide procedures grew approximately 18%, and the installed base grew to 9,539, an increase of 15% compared with Q3 2023. Revenue jumped 17% to $2.04bn, while net income rocketed 36% to $565m.

Powerful business model

What I like here is that the vast majority of Intuitive’s revenue is recurring (83% last year). You see, every surgery with the robots require specific instruments and accessories that need regular replacement, generating consistent sales.

And as more systems are installed, this creates a recurring-revenue flywheel, where more installed systems drive more demand for accessories and services. Replacement instruments and accessories contributed 62% of total revenue for Q3.

Plus, once the firm’s products are installed in hospitals and surgeons are trained on them, there are very high switching costs. In other words, highly skilled professionals comfortable with the da Vinci system are unlikely to want to switch. This gives Intuitive a wide competitive advantage (or moat).

What am I waiting for?

That all sounds great, so why wait for a big dip before buying more shares? Well, after surging by around 100% in the past year, the stock is very expensive. At $513, it’s trading on a price-to-earnings (P/E) ratio of 82.

While the stock is rarely ever cheap because of the firm’s dominant competitive position and high-quality revenue, that’s still very pricey. In fact, its above the five-year P/E average of 72.

Also, Intuitive isn’t without risk, as shareholders found out during the pandemic when many elective operations were postponed. Revenue took a hit and the stock dropped 35% in one month in early 2020.

Therefore, another global pandemic is a key risk, while the company faces increasing domestic competition in China.

A bright future

Still, I’d love to own more shares (at the right price) for the long term. The company’s next-generation da Vinci 5 system offers improved 3D vision for greater surgical precision, and increased computing power and data-gathering capabilities, offering the potential for self-improvement.

Looking ahead, the global market for robotic surgery appears nowhere near saturation point. According to most estimates, it’s set to grow briskly at a compound annual rate of around 17% through to 2030.