Amazon's stock is up big this year, but hedge-fund legend Stanley Druckenmiller thinks the e-commerce giant's shares have more room to run.

"I love Amazon. This company, which everybody keeps quoting the multiple, is selling for less than three times sales. The S&P 500 is selling for over two times sales," Druckenmiller, the chairman and CEO of the Duquesne Family Office, told CNBC's Kelly Evans on "Closing Bell" on Tuesday.

Amazon shares have skyrocketed higher by more than 55 percent this year, but the sharp increase has elevated the stock's price-to-earnings multiple, a metric used to value stocks. According to FactSet, Amazon was trading at a multiple of 296. By comparison, the was trading at a price-to-earnings multiple of 22.

But Druckenmiller said the e-commerce giant is "intentionally underearning," noting Amazon is reinvesting capital back into its businesses instead. Druckenmiller also praised Amazon CEO Jeff Bezos, saying "I think Bezos is incredible."

Druckenmiller also praised Tencent, a Chinese technology company.

"I really like Tencent, and I really like their position. They're in payments, they've got their own version of Netflix, they've got their own version of cloud, WeChat is probably the best platform on the entire planet for all of it, and then they have a gaming business," Druckenmiller said. And like Amazon, "Tencent is intentionally underearning, and the long-term growth looks incredible."

Tencent's Hong Kong-listed shares have more than doubled this year, rising 104 percent. Druckenmiller said he owns Tencent shares.

However, there is one tech giant Druckenmiller is not wild about: Apple. During the interview, he said: "I don't find [it] nearly as exciting as say, Amazon, Facebook or Google."

He said Apple's products are great, "but they're probably no better than Samsung's."

On the smartphone maker, he added, "I just don't see the underearning that I see in these other companies."

The investor said he does not own Apple or have a short position against the company.

Druckenmiller's hedge fund generated annualized returns of 30 percent during his investment career. The investor has a net worth of $4.7 billion, according to Forbes.