Alphabet (GOOGL) - Get Report revealed a bit more than usual on its latest earnings call. 

Shares of Alphabet jumped 9% in after-hours trading after the tech giant topped estimates on the top and bottom lines, posting earnings of $14.21 per share on revenue of $38.9 billion versus expectations of $11.30 per share on $38.15 billion in revenue. It also announced a stock repurchase of $25 billion. 

On a call with investors, CEO Sundar Pichai revealed that Google Cloud Platform has an annual run rate of $8 billion -- a metric that it has not regularly disclosed despite talking up the progress of the segment in more qualitative terms. By contrast, Pichai dodged a question about Google Cloud revenues on Alphabet's April earnings call.

The disclosure from Alphabet brass, who usually err on the side of ambiguity on quarterly earnings calls, was applauded by analysts eager for more details on the breakdown of Alphabet's business performance. 

The $8 billion run rate -- a metric that refers to a projection of revenues this year -- includes Google Cloud Platform (GCP) as well as G Suite, now led by Google Cloud CEO Thomas Kurian, who took the helm at the division earlier this year. In April, Alphabet unveiled Anthos, a revamped cloud services platform intended to attract enterprises that rely on hybrid cloud environments. Google is presently a distant third in the cloud market, behind Amazon and Microsoft (MSFT) - Get Report .

"Overall, GCP remains one of the fastest-growing businesses within Alphabet and we're really pleased with how the team is executing on both," said CFO Ruth Porat.

The last time Alphabet put a number on cloud revenues was in early 2018, when it said the segment brought in $1 billion in revenue the prior quarter -- suggesting that the segment's annual revenues have approximately doubled since that time. 

In her remarks, Porat also provided slightly more detail on the biggest contributors to Alphabet's revenue growth, as well as the rationale behind certain expenditures like hiring and data centers. Google cloud was the third-largest driver of revenue growth, behind mobile search and YouTube, she said. 

There was one issue that Alphabet executives remained tight-lipped about, however: A DOJ antitrust probe of the company, which was reported earlier this year and confirmed by the agency this week in a statement. Without naming specific companies, the DOJ said it was investigating "market-leading online platforms;" Apple (AAPL) - Get Report , Amazon (AMZN) - Get Report and Facebook (FB) - Get Report are also being investigated. 

"To the extent there are questions, we will engage with those constructively; to the extent there are concerns, we will address those as well," Pichai said, without acknowledging the investigation directly.

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