Out of the mega-cap tech stocks, Apple (AAPL - Get Report) is closest to the $1 trillion market cap. Alphabet (GOOGL - Get Report) or Amazon (AMZN - Get Report) could cross the line first, analysts suggest, if the convergence of hardware, software, cloud, media, retail and other forces drives valuations higher.

Apple has a nearly $805 billion market cap, and would need a 25% boost in valuation to reach a $1 trillion valuation.

Tax cuts could put the company close, RBC Capitl Makrets analyst Amit Daryanani wrote in report this week. If the administration and Congress can lower the federal tax rate and pass a holiday on repatriated cash, among other steps, Apple's earnings could rise by $4 to $4.50 per share, the analyst suggests. The analyst sets a target of $180 per share, or more than 15% upside to Tuesday's close of $155.90.

Google parent Alphabet is further from the mark with a $678 billion market capitalization. However, Jefferies analyst Brent Thill suggests in a recent report that the company "has the right pieces in place to win the race to $1Tn." Thill's target price is $1,200, or more than 23% above the stock's $972.60 close on Tuesday.

Google search and YouTube still have growth opportunities, Thill suggested, while Google's growing portfolio of hardware, its prowess in artificial intelligence and its growing cloud business could push its valuation past Apple's. 

Google released a slew of hardware and software updates at its product event on Oct. 4. "In our view this provides a significant competitive advantage as Google is now one of the only companies in the world (Apple may be the only other) offering a comprehensive suite of sophisticated product offerings," Thill suggested. Google's lineup inlcudes the Pixel 2 phone to Chromebook Laptops, Google Home smart speakers and Nest home devices, among others. Google Assistant's strong speech recognition, the Google Lens visual search and Google Translate make the products stronger and give Alphabet an advantage, he suggested. 

Moreover, Google Cloud Platform could be a "break-out play for shares" if the company provides more detail about the business' performance, Thill added. Since Amazon and Microsoft started to disclose more information about their cloud businesses, the analyst noted, the stocks gained 150% and 50%, respectively. Amazon broke out results for its cloud in 2015; Microsoft does not fully disclose results for its Azure cloud operations but provides more information than Google. Thill projects that Google Cloud Platform's market share will grow from 6% market share in 2016 to 13% in 2018, while Microsoft Azure's share expands from 18% to 19% and Amazon Web Service's market share drops from 77% to 68%.

New York University Stern School of Business professor Scott Galloway recently told TheStreet.com that Amazon is "winning everywhere it touches" up against Apple, Alphabet and Facebook (FB - Get Report)  and will be the first to $1 trillion valuation. The company is less than half-way there as of Tuesday, with a $473 billion market cap after Tuesday's close at $987.20. 

Amazon could follow up its purchase of Whole Foods by acquiring Nordstrom (JWN - Get Report) , Galloway suggested, and beat the cable networks at their own game by purchasing "The Walking Dead" parent AMC Networks (AMCX - Get Report) .

TheStreet's Brian Sozzi and Scott Gamm discuss Apple hitting a $2 trillion market cap.

Alphabet, Apple and Facebook are holdings in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio. Want to be alerted before Cramer buys or sells GOOGL, AAPL or FB? Learn more now.

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Editors' pick: Originally published Oct. 11.