HubSpot shares rallied 8% on Tuesday after CNBC’s David Faber reported that Alphabet is looking at an all-stock offer for the software company.

Reports of a potential deal first surfaced in early April, when Reuters published a story saying Alphabet was talking to advisors about making an offer for HubSpot. Bloomberg followed with a story earlier this month, indicating that talks were progressing.

“There have been many reports about HubSpot being in conversations with Google,” Faber said Tuesday. “My understanding is absolutely true, all-stock deal for Alphabet to acquire HubSpot.”

With a market cap of about $33 billion, after Tuesday’s jump, HubSpot would be by far Alphabet’s largest deal ever. Google’s biggest acquisition to date was the $12.5 billion purchase of Motorola Mobility in 2011.

HubSpot is primarily used for marketing by small- and medium-size businesses. Its products would presumably fill a gap in helping Google provide marketing technology and customer relationship management tools to its customers, potentially bolstering cloud revenue.

HubSpot shares were up slightly for the year prior to Tuesday’s gains, closing the day at $638.39. The stock doubled in value in 2023.

Alphabet did not immediately respond to CNBC’s request for comment. HubSpot declined to comment.

— CNBC’s Jordan Novet contributed to this report.