Dropbox has raised $325 million with the option to go for $450 million, according to a new SEC filing (hat tip to Fortune’s Erin Griffith for spotting it). Those figures are sort of in line with January estimates that the company had raised about $250 million, with an upside limit of $400 million for an overall valuation of $10 billion.

Update: Fortune updated the story to say Dropbox has, in fact, raised $350 million in this round, for a $10 billion valuation, figures Dropbox confirmed for re-Code. It’s unclear if Dropbox will pursue the full $450 million.

San Francisco-based Dropbox is a huge hit with consumers who want to share and sync their files across devices and store them in the cloud. Last fall the company said it had more than 200 million users, although it always declines to say how many of them use the paid version of the…