Shares of the Temple City, Calif., company at last check were rising 2.4% to $87.57.
Fulgent Genetics swung to adjusted earnings of $6.20 a share from a loss of 4 cents in the year-earlier period. The FactSet consensus called for earnings of $3.94 a share.
Revenue totaled $295 million, up from $8.4 million a year earlier and beating the FactSet consensus of $199.5 million.
The company delivered about 2 million billable tests in the quarter.
Looking ahead, company expects to generate revenue of at least $325 million in the first quarter.
It forecasts full-year 2021 revenue of about $800 million, growth of 90% from 2020.
FactSet's consensus calls for first-quarter revenue of $287.9 million and full-year revenue of $708.6 million.
Fulgent Genetics expects about $70 million of 2021's sales to come from next-generation-sequencing testing, with the remaining $730 million coming from non-NGS testing.
NGS technology is a genetic testing technique that enables millions of DNA fragments to be sequenced in parallel, which the company said has dramatically lowered the cost and improved the quality of genetic testing.
"While we did not envision 2020 to unfold in the way that it did, I am proud of our team for supporting the pivot of our business to rapidly scale to become one of the top providers of COVID-19 testing in the country," Ming Hsieh, chairman and CEO, said in a statement.
Hsieh said that although the majority of the company's business was "from COVID-19 testing, we believe we have laid a very strong foundation for continued growth in the years ahead."
In December, the company said that it had extended its contract to provide daily COVID-19 testing to New York City public-school students throughout the 2021 school year.