Some might say that it would be best to avoid investing in the healthcare sector this year. It frequently doesn't perform as well as the broader market during U.S. presidential election years. And that could be true again in 2020, especially with several leading candidates advocating changes that could dramatically disrupt the businesses of many healthcare companies.

However, some companies in this industry appear to be great picks regardless of what happens on the political scene. Here are three healthcare stocks that you can buy in February that should be big winners over the long term.

Physician holding stethoscope up to healthcare icons

Image source: Getty Images.

1. Guardant Health

Guardant Health's (NASDAQ:GH) liquid biopsy products -- blood tests that detect DNA fragments from tumor cells -- are changing the landscape for cancer treatment. The company currently markets two tests: Guardant360, which matches cancer patients with treatments, and GuardantOmni, which helps drugmakers screen patients for clinical studies of cancer drugs. 

These two products have fueled tremendous growth for Guardant Health. Its revenue soared 181% year over year in the third quarter of 2019. Sales are poised to move even higher with two big catalysts likely on the way soon: FDA clearance for Guardant360 and a Medicare national coverage determination (NCD) that would establish reimbursement for Guardant360 for all Medicare beneficiaries in the U.S.

But two of its other products hold even greater potential. The company currently offers its Lunar-1 and Lunar-2 liquid biopsy assays for research use only. Lunar-1 monitors for cancer recurrence. Lunar-2 enables early screening for cancer. The annual market opportunity for Guardant360 is believed to be around $6 billion, but the Lunar products could have a total addressable U.S. market of more than $45 billion. 

I picked Guardant Health as a top healthcare stock to buy in January, and it's still at the top of my list this month. The company has a head start in developing liquid biopsies and has several near-term catalysts. My view is that its remarkable growth will continue no matter who sits in the White House.

2. Livongo Health

Livongo Health (NASDAQ:LVGO) also claims a great growth story. Its revenue soared 148% year over year in the third quarter, and it nearly doubled both the number of its organizational clients and its patient-members in 2019.

Livongo's success is driven by an impressive data-driven chronic disease management program. The company's primary focus is on diabetes, where as a group, its members have demonstrably improved their blood sugar levels and blood pressure, and lost weight. And Livongo's personalized program saves money for all parties involved too, achieving an average of $1,908 per diabetes patient per year in gross medical savings.

The company has a massive market opportunity, and it's really just getting started. While it has over 200,000 diabetes members, that's a drop in the bucket compared to the 31.4 million people who live with the disease, or the half a million or so individuals who get diagnosed with it each year.

In addition to diabetes, the company is also focused on hypertension and weight management. Livongo thinks that it has an annual market opportunity of $46.7 billion in the U.S. alone. CEO Zane Burke said in November that the company is evaluating when it should move into international markets. 

3. Teladoc Health

Teladoc Health (NYSE:TDOC) is another company that's changing healthcare as we know it. It's the leader in providing telehealth services, and its revenue has hit a compound annual growth rate (CAGR) of more than 60% over the last three years.

It's not surprising that 40% of the Fortune 500 and thousands of smaller organizations use Teladoc Health's services. Its virtual care approach lowers healthcare costs while increasing convenience for patients by giving them the ability to consult medical professionals remotely.

Even though Teladoc's growth has been impressive, it still has plenty of room to run. For example, the company currently has 54 million U.S. members, but there are another 75 million potential members at current Teladoc Health clients. The portion of the U.S. market that it hasn't reached yet represents an additional 191 million prospective members.

Teladoc also continues to make strategic acquisitions. The company's pending $600 million buyout of InTouch Health will expand its platform to include provider-to-provider telehealth, further solidifying its dominance in its niche.