What happened

Shares of eHealth (EHTH -2.21%) were up 29.7% as of 10:50 a.m. EST on Friday after the online health exchange provider announced preliminary fiscal 2019 fourth-quarter and full-year results after the market closed on Thursday. The company expects fourth-quarter revenue will be between $257.5 million and $259.5 million with earnings between $53 million and $55 million.  

So what

Companies often like to provide a sneak peek at their results before their official quarterly updates when those results are very good. And that's definitely the case for eHealth.

Person holding touchscreen tablet with an online health insurance app displayed

Image source: Getty Images.

The consensus Wall Street analysts' estimate for the company's Q4 revenue is $194.9 million. eHealth blew past that estimate and even topped the most optimistic analyst's revenue projection of $230.5 million.

How did eHealth outperform expectations in such spectacular fashion? CEO Scott Flanders pointed to the "exceptional performance by our team during the fourth quarter Medicare annual enrollment period." The company's Medicare membership soared by 88% year over year in Q4 with its Medicare Advantage membership more than doubling from the prior-year period.

Now what

Flanders said, "We remain excited about the Medicare market opportunity and significant growth potential ahead of us and are looking forward to sharing our outlook for 2020 as part of our fourth-quarter earnings release next month." That 2020 outlook appears likely to be a very good one based on eHealth's preliminary Q4 numbers.

However, healthcare stocks could be in for a bumpy ride this year with the upcoming U.S. presidential elections. Several of the leading Democratic presidential candidates are advocating agendas that could derail eHealth's growth.