Amazon shares, which are up 82 percent since January, rose by $26.20 to $119.65 Friday, making Chief Executive Jeff Bezos richer by about $2.47 billion (1.51 billion pounds).

According to Reuters data, Bezos directly held 94,158,586 Amazon shares as of August 18.

Trading volume for the online retailer's shares rose to more than 25 million shares -- four times their 50-day moving average.

Jefferies & Co upgraded the stock to "buy" from "hold," while FBR Capital Markets raised it to "outperform" from "market perform," citing accelerating growth in media and international business, and strong cash-flow generation.

"Amazon's surprisingly strong results attest to a recovering consumer," Jefferies' Youssef Squali said, adding that the company has a user-friendly platform and a superior product mix at competitive prices.

FBR said it expects sales of the Kindle electronic reader, Amazon's bestselling product in units and dollars, to accelerate with the international launch and recent price reduction.

Goldman Sachs said it continues to believe that Amazon can double its market share the next several years. The overall e-commerce market is also expected to double over the same period.

"We believe Amazon is a best-in-class retailer with significant long-term growth potential," said Standard & Poor's Equity Research analyst Michael Souers, who raised the stock to "hold" from "sell."

Amazon is clearly gaining share and its pending acquisition of shoe seller Zappos.com should help fuel market penetration in new categories, Susquehanna analyst Marianne Wolk said in a note to clients.

On Thursday, Amazon's quarterly results handily beat estimates as it saw strong demand in North America and abroad. It also indicated that holiday sales could come in far above expectations.

(Additional reporting by Nivedita Bhattacharjee in Bangalore; Editing by Anne Pallivathuckal)