What happened

Shares of Teladoc Health (TDOC -3.82%) rocketed 128% higher in the first six months of the year, according to data from S&P Global Market Intelligence. The telehealth leader is enjoying booming demand for its services.

So what 

With the coronavirus pandemic stretching hospitals around the world to their maximum capacity, health officials are desperately seeking new ways to deliver more care to more people. Telehealth services -- which help doctors and other healthcare professionals provide medical consultations via videoconferencing apps on patients' desktop computers and mobile devices -- are one of the best ways to do so.

A man speaking with a doctor via a videoconferencing app on his computer.

Teladoc is helping more people receive virtual care. Image source: Getty Images.

As the leading virtual care platform, Teladoc is growing at a torrid rate. Its first-quarter revenue climbed 41% year over year to $180.8 million, fueled by a 61% rise in U.S. paid memberships and a 92% surge in patient visits. 

Now what

Teladoc is already off to a strong start in the second half of the year. After strong gains in the first few days of July, the stock is now up 150% so far in 2020. Yet even after the stock's sharp rally, more gains may lie ahead for investors.

Teladoc is still early in its growth cycle. The rapidly expanding company pegs its potential patient base at as much as 1.1 billion people, which places its current customer count at only about 1% of its massive addressable market.