Fastly shares tumbled 26% in premarket trading.
Though the company's fourth-quarter revenue and adjusted loss per share were both better than analysts' consensus forecasts for the two metrics, management's disappointing outlook may have spooked some investors.
Fortunately, fourth-quarter growth was better than expected, with Fastly's top line rising 13% year over year to $97.7 million, beating analysts' average forecast for revenue of $92.5 million. The company's adjusted loss per share of $0.10 was also notably narrower than analysts' average estimate for a loss per share of $0.16.
Customer count at the end of the quarter was 2,804 -- up from 2,748 in the third quarter of 2021 and 2,326 in the year-ago period. But the year-over-year growth in customers was helped by the company's new customers from its acquisition of security specialist Signal Sciences.
Despite reporting solid fourth-quarter results relative to expectations, the company's guidance for 2022 revenue to be between $400 million and $410 million was below analysts' average forecast for revenue of $419 million. In addition, the company's expectations for its profitability in 2022 disappointed. Fastly said it expects its adjusted loss per share to be between $0.50 and $0.60 this year -- wider than a consensus forecast for $0.48.