How Alibaba stacks up to other tech titans

Alibaba Group Holdings Ltd.
Chance Chan | Reuters

Alibaba is set to price tonight between $66 and $68 per share in what will likely be the largest global IPO ever. Assuming it prices at the higher end of the range (as some are expecting), Alibaba's market cap will reach roughly $175 billion.

Many analysts think this valuation is just the beginning for the online retail giant.

"If they continue growing at this 50 percent clip ... I think they can justify this valuation," said Santosh Rao, head of research at Manhattan Venture Partners.

Read MoreAlibaba to price within existing range: Sources

How would that stack up against other technology titans? At $175 billion it would be among the very top.

Facebook Alibaba Holdings Group Ltd.
Adam Jeffery | CNBC

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.

Read MoreAlibaba won't pull page from Facebook IPO, but is it safe?

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.

S&P Tech Sector Valuations

Ticker Company Market Cap (Billions)
AAPL Apple Inc. $608
GOOGL Google Inc. Class A $398
GOOG Google Inc. Class C $398
MSFT Microsoft Corporation $383
FB Facebook, Inc. Class A $199
IBM International Business Machines Corporation $192
ORCL Oracle Corporation $183
INTC Intel Corporation $173
V Visa Inc. Class A $134
CSCO Cisco Systems, Inc. $128
QCOM QUALCOMM Incorporated $127

Read MoreAlibaba's new frontiers mean risky business

With Alibaba's massive presence, some market strategists have raised questions over whether the IPO will saturate the market, especially within the tech sector.

Rob Sanderson is managing director and senior analyst covering the Internet sector at MKM Partners. He says that while some investors have made room for the online retail giant's IPO in their books, there is still space in the sector.

"Let's not forget that the supply of stocks has been narrowed all year," Sanderson said. "There's a lot of buyback and M&A activity in the tech sector and that's putting a limit on supply. So the market can absorb these big events like the Alibaba IPO. Maybe there's a little bit of wiggling around on tech books in advance of it but that's not a sustainable move."

Read MoreTop fund manager passes on Alibaba IPO

—By CNBC's Elizabeth Schulze and Dominic Chu