Less than a year ago, reports were circulating that on-demand car service Uber was closing in on a $1 billion valuation. Now that looks like pocket change.

Last week, the company's reported valuation jumped quickly from $10 billion to $12 billion. On Sunday, a new number made the rounds: $17 billion.

See also: A Top New York Taxi Commissioner Is Joining Uber

The Wall Street Journal reports that the latest funding round for the company has attracted a lot of interest from investors, prompting a run-up in its valuation. The swooning numbers have scared off at least one potential investor: The investment firm General Atlantic passed after the quoted valuation was around $14 billion, the Journal reports.

Reps from Uber could not be reached for comment.

Last week, Uber was said to be looking to raise $500 million. Now that the valuation figure has inched higher, the round could be $100 million or so north of that, according to the report.

At $17 billion, Uber would be worth more than Airbnb ($10 billion), Dropbox ($10 billion) and Spotify ($4 billion.) It would also be roughly on par with WhatsApp, which Facebook is purchasing for a total of $19 billion. For comparison's sake, Twitter's market cap on Monday was $17.9 billion.