One rival it would surpass is Internet retailer Amazon.com, which has a market capitalization of $151 billion. Amazon's stock has dropped almost 20 percent in 2014, after its series of bets on new products and services like the Fire Phone and grocery delivery.
Alibaba's valuation is more than twice the size of another online retailer eBay, currently valued around $65 billion. The company's stock has dropped about 4 percent this year, but has still seen huge returns since it went public in September 1998.
A stellar first day of trading for Alibaba could bring the company within reach of Facebook's overall value. The social network site's market cap topped $200 billion two weeks ago, roughly doubling its value from when it went public in May 2012.
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Of course, Apple leads the charge among tech giants with a nearly $608 billion market value. In fact, the Cupertino, California-based behemoth has the largest market cap in the overall S&P 500 by nearly $200 billion. (Exxon Mobil comes in second at roughly $415 billion.)
Interestingly, Apple's massive $165 billion cash pile alone is almost as big as Alibaba.
The other S&P tech companies with a higher valuation would be Microsoft, Oracle, Google and IBM.