Alphabet was on track to hit a historic $4 trillion market valuation on Tuesday, powered by an impressive year-long rally fueled by the Google parent's sharpened focus on artificial intelligence tools.

Shares of the company were up 4.1 percent at $331.7 in premarket trading, putting the company on course to breach the key milestone at the open.

READ MORE: Alphabet shares hit record after Berkshire tech bet with $4.9b stake

The search and ad tech giant joins an elite club of Big Tech companies racing to dominate the booming technology as AI continues to captivate Wall Street this year.