Goldman Sachs doubled its estimated value of Alibaba, China’s e-commerce giant, on Monday, to $70 billion from $35 billion earlier. Goldman Sachs made the assessment in a report for Yahoo (Nasdaq: YHOO).

Lu And Ma Jonathan Lu, right, Alibaba's new leader, with Jack Ma, its legendary founder in the background Photo: Reuters/China Daily

Alibaba was founded in 1999 by Jack Ma, who recently stepped down as the company’s CEO. Alibaba owns, a B2B portal, and, China’s largest B2C platform. The company acquired Yahoo China in 2005 and recently purchased 18 percent of Weibo, China’s most popular microblogging site, owned by Sina (Nasdaq:SINA).

Alibaba has been gearing up to complete its IPO this year, with estimates as high up as $100 billion. Goldman Sachs is a top U.S. investment bank.