Alphabet on Thursday reported quarterly earnings that beat analysts' expectations.
The parent company of Google posted earnings of $8.42 a share on $21.5 billion in revenue. Quarterly sales rose 21 percent year over year. Wall Street expected the company to report earnings of $8.04 a share on $20.76 billion in revenue, according to a Thomson Reuters consensus estimate.
CFO Ruth Porat said in a statement that the results "reflect the successful investments we've made over many years in rapidly expanding areas such as mobile and video."
Both Class A and Class C shares of Alphabet gained more than 4 percent in extended trading. The former briefly traded above its record intraday high of $810.35. The Class A shares have since pared those gains.
Last year, Google's founders changed the company's structure, creating Alphabet as a holding company of sorts. Core Google generates most of the company's money, and a separate category called "other bets" includes projects like Google Fiber, Nest Thermostats, science initiatives Calico and Verily, and the investment arm Google Ventures.
Alphabet reported that revenue for the latter segment came in at $185 million for the quarter, above analyst expectations of $168.2 million in revenue, according to a StreetAccount consensus estimate.
One of the projects in the "other bets" category is Alphabet's self-driving cars. During the company's Thursday afternoon earnings webcast, Porat said the company is now testing driverless cars in Mountain View, California; Austin, Texas; Kirkland, Washington, and Phoenix. She added that the company has conducted self-driving tests that total more than 1.6 million miles.
Porat said that Alphabet's approach to driverless cars is different from the way other companies are approaching the space.
"We're focused on fully autonomous cars because in early testing we saw the risk of depending on drivers to remain engaged once you give them the option to switch off. So we've invested a lot there. We're testing extensively based on this approach," she said.