Google's shares have passed $700 for the first time, lifted by reports it plans to enter the mobile phone market.
Google's shares have risen by $100 in the last month alone
Its stock rose 1.7% to $707 on Wednesday on rumours it is working with US networks Verizon and Sprint Nextel.
While none of the firms have commented, Google is said to be looking at mobile phones that run on its software.
The value of Google's shares have now risen eightfold since they were first floated in August 2004, as its profit growth continues to dazzle.
It is now the fifth largest US company by market capitalisation, worth a total $219bn (£105bn), surpassed by only Exxon Mobile, General Electric, Microsoft and AT&T.
'Make a splash'
Analyst Avi Greengart of Current Analysis speculated about how Google would be able to tempt mobile phone networks to use its phones.
"If Google is going to make a splash, it's going to have to say [to operators], 'Offer our phone and we'll share the revenue,'" he said.
Last month, Google saw its net profit for the three months to end of September soar 46% to $1.07bn, compared with $733.4m for the same period last year.
Google's share price has risen by $100 since then.
The world's most popular internet search engine, Google makes the bulk of its money from advertising.
Last year, it spent $1.65bn buying video-sharing website YouTube.
Google's shares were priced at $84 when they debuted in 2004.