Amazon's stock will double in the next three years, noted investor Bill Miller told CNBC on Monday.
"Amazon's addressable market is so gigantic," said Miller, founder of Miller Value Partners and a longtime Amazon bull.
The tech giant, up 2.77 percent in afternoon trading, is now the most valuable public company in the world. It overtook Microsoft on Monday morning after reaching a market value of about $790 billion. Microsoft's market value stands at about $785 billion. In September, Amazon reached a $1 trillion market cap for the first time before losing ground in the late-year sell-off.
However, despite that sell-off, Amazon is still up 30 percent over the last 12 months, Miller told Kelly Evans on the new CNBC show "The Exchange."
And while there has been a lot of talk about regulating tech companies, Miller is unconcerned about Amazon being broken up. For that to happen, antitrust laws would have to be changed and "they can't agree on anything in Congress. That's a long way off, if it happens," he said.
Meanwhile, Miller's fund, Miller Opportunity Trust, is "off to a very strong start this year," after having a "pretty bad" 2018.
He blamed last year's performance on the December rout, saying the sell-off "really, really hit us."
"At the end of the third quarter, I think we were about 700 or 800 basis points ahead of the market," he said. "We gave all that back and more in the fourth quarter."
Miller, a star money manager at Legg Mason for decades, is best known for beating the for 15 consecutive years through 2005. His track record more recently, particularly during the financial crisis, has been up and down.
In 2016, he went out on his own, forming Miller Value Partners.
A year later, he bought two mutual funds that he started at Legg Mason. The bigger of the two, Miller Opportunity Trust, beat the S&P 500 in 2017. But the fund trailed the index by about 6 percentage points last year.
Stocks, in late Monday trading, were adding to Friday's massive gains of more than 3 percent for the Dow Jones Industrial Average and the S&P 500. The Nasdaq on Friday was up more than 4.2 percent. However, Monday's advance was not nearly enough to bring the Dow, S&P and Nasdaq out of correction territory.
The two-day rally came after Federal Reserve Chair Jerome Powell on Friday said the central bank would be "flexible" in its approach to monetary policy. Stronger-than-expected employment data also contributed to Friday's sharp gains.