What happened

Shares of telehealth leader Teladoc Health (TDOC -2.91%) soared 139% in 2020, according to data from S&P Global Market Intelligence. That performance made it one of the year's best performers among large-cap stocks (stocks with market caps of at least $10 billion).

For context, the S&P 500 index returned 18.4% last year.

Person's hands holding a cell phone which has a young male doctor on the screen.

Image source: Getty Images.

So what

We can naturally attribute Teladoc stock's powerful performance in 2020 to the COVID-19 pandemic. The crisis has been driving people toward consulting with healthcare providers virtually rather than in person.

We can't quantify exactly the pandemic benefit to Teladoc's business since we can't know how fast it would be growing if the crisis had never occurred. However, this chart data should give you a ballpark idea:

Quarter

Portion of Quarter the Pandemic Affected

Revenue Growth YOY

Total Number of Visits Growth YOY

Q4 2019 None 27% 44%
Q1 2020 Approx. 2 weeks 41% 92%
Q2 2020 Entire 85% 203%
Q3 2020 Entire 109% 206%

Data sources: Teladoc earnings reports. YOY = year over year.

The second and third quarters also got a boost from Teladoc's acquisition of InTouch Health, a hospital-based telemedicine company. The deal closed on July 1.

TDOC Chart

Data by YCharts.

Now what

Teladoc hasn't yet announced the date of its release of its fourth quarter 2020 results, but it will probably be around late February. Those results will include two months of contribution from Livongo Health, as Teladoc closed on this $18.5 billion acquisition on Oct. 30. Livongo provides digital tools for helping people with diabetes and other chronic conditions improve their health.

For the fourth quarter, management guided for revenue in the range of $294 million to $304 million and total visits to be between 2.8 million and 3 million. At the midpoints of these ranges, this represents year-over-year growth of 92% and 142%, respectively.