Investing is an ongoing journey. No investor is perfect, and no investment is entirely devoid of risk.

However, when you adhere to the philosophy of investing in a wide variety of markets -- both bull and bear and those in between -- and only put your money into businesses you understand and believe are wise long-term investments, you don't need to rely on ill-fated approaches like market-timing to boost your returns. 

Building a well-diversified portfolio takes time. If you have cash on hand that you can put into stocks right now, and leave alone for several years at least, there's no shortage of amazing businesses with compelling buying opportunities for long-term investors. Here are two such companies to consider hitting the buy button on right now. 

1. Teladoc 

Teladoc Health (TDOC -3.76%) is still trading down by more than 60% from a year ago. Sentiment around growth stocks has continued to affect the telehealth giant as have mixed investor views about its future growth ability in an atmosphere that appears to be moving further away from the worst of the pandemic.

However, there remain an abundance of green flags for this stock, and for investors with a multi-year, buy-and-hold horizon, the company is anything but the relic of a bygone investing era. 

Revenue growth remains strong and significantly elevated from pre-pandemic levels. In fact, the company recorded revenue of $2.4 billion in 2022, which was up 18% from 2021 and more than four times higher than its revenue in 2019. Teladoc closed out 2022 with a net loss just shy of $14 billion. Almost all of this was derived from non-cash (important to emphasize as these losses weren't operational in nature) impairment charges related to its Livongo acquisition a few years ago.

Teladoc is continuing to see meaningful adoption across its core business segments, including its primary care offering, chronic care segment, and BetterHelp, its teletherapy wing. At the end of 2022, more than 80 million people had access to Teladoc's virtual care platform. More than half had access to more than one of the company's products, largely due to the continued growth of its partnerships with insurers and companies across a range of industries.

Of the people enrolled in Teladoc's chronic care program, 30% are using more than one offering. Bear in mind, approximately a third of people worldwide have one or more chronic illnesses, representing a chronic disease management market on track to hit a valuation of $15 billion by the year 2031. As for the company's teletherapy business, more than one million people used this offering to access mental healthcare services in 2022 alone.

Teladoc remains among the largest telehealth providers globally by revenue, with a footprint that spans more than 130 countries and counting. The healthcare company's focus on expanding access to primary care as people continue grappling with lack of affordable and accessible healthcare options -- and its continued disruption of underserved markets like chronic care and mental healthcare -- signal a growth story that's far from over.

Patient investors may want to capitalize on this trend in the current market and well beyond.  

2. Intuitive Surgical 

Intuitive Surgical (ISRG -0.78%) has remained the leader in the field of surgical robotics for more than two decades now. The company has built a resilient and profitable business around the success of its flagship product, the da Vinci Surgical System, which is approved for use in a wide range of surgeries from colorectal to cardiac to thoracic procedures, and more. There are several generations of the da Vinci system currently on the market.

Intuitive Surgical has a second core product called the Ion (used in minimally invasive lung biopsies), which it added to its portfolio of approved products in 2019. Intuitive Surgical has a lengthy history of profitability and growing its revenue steadily. Over the past decade, Intuitive Surgical has seen revenue and profits soar to the tune of 175% and 97%, respectively.  

If you narrow that lookback period to five years, annual revenue and earnings have jumped by respective amounts of 67% and 17%. Intuitive Surgical closed out 2022 with 7,544 of its da Vinci systems installed globally. This installed base figure represented an increase of 12% on a year-over-year basis. However, that installed base amount was up 35% from pre-pandemic levels at the end of 2019.  

So, you might be wondering, why is Intuitive Surgical still trading down by about 14% over the last year? Well, COVID-19 resurgences in key markets like Europe and Asia in 2022 saw many surgical procedures postponed. That affected procedure volume, which meant decelerations in Intuitive Surgical's top and bottom lines. 

However, Intuitive Surgical is still growing revenue steadily. It's also continued to be profitable. And as noted earlier, the company is still exhibiting strong growth on a multi-year basis. Most of the procedures performed using Intuitive Surgical's systems aren't elective, and even short-term delays don't have anything to do with the underlying business here. Investors looking at at a three- to five-year minimum investment in this stock shouldn't be put off by these near-term factors.

The continued market dominance of this business -- Intuitive Surgical's market share stood around 80% in 2021 -- coupled with its ongoing profitability and continued provider adoption of its products make this stock a no-brainer buy in my book.