Why Was Backblaze Stock Up on Aug 4, 2026?

Backblaze's growth used to be a consumer and small-business backup story. It is now, by its own numbers, an AI-infrastructure story: B2 Cloud Storage, the segment growing 34% year over year, is being sold explicitly as capacity-tier storage for AI workloads, and the company disclosed a $335 million multi-year agreement with CoreWeave — an AI-cloud infrastructure provider — as the proof point. That single detail is doing more to explain the stock's reaction than the earnings beat itself.

The numbers behind the reaction

Revenue reached $42.71 million, up 18% year over year and ahead of a $39.93 million estimate; adjusted earnings per share were $0.08 against a $0.02 estimate. Annual recurring revenue hit $177.3 million, up 21%. The company raised full-year guidance to $172 million-$174 million, comfortably above a $162.3 million analyst estimate. Shares rose 13.63% in the regular session and added a further 17.19% after hours.

Why the AI-storage framing matters more than the beat

A traditional cloud-backup business competes on price against much larger providers with thinner margins to work with. Positioning as "capacity-tier" storage for AI workloads -- cheaper, slower storage that sits behind the expensive, fast storage AI training and inference actually run on — is a different, less commoditized business, and a named $335 million customer commitment from an AI infrastructure company is concrete evidence that positioning is landing with real, large buyers rather than just being investor-relations language.

What to watch

Whether B2's 34% growth rate holds or accelerates as more AI-workload customers sign multi-year deals like CoreWeave's, since that segment's growth rate — not the legacy backup business — is now the number that determines whether this quarter's re-rating was justified.