Search engine giant Google has seen its shares rise above the $600 mark for the first time, with investors confident ahead of third-quarter earnings.
Google shares started at $85 when it listed
Shares traded as high as $610.26 on Monday, before closing at $609.62.
Since going public in August 2004, Google's stock has risen sharply from its original price of $85 a share.
The firm has tapped into growing sources of revenue from advertisers who are turning away from more traditional media including TV and print.
Investors were recently buoyed by figures showing the firm had improved its reach compared with Yahoo and Microsoft.
Larry Page and Sergey Brin, who founded the search engine, have seen their wealth rise to $20bn each.
In the past month alone, Google has seen its shares increase 17% while they have risen 32% since the beginning of 2007.