Yahoo's stock is soaring, gaining 100 percent over the last year. But it's not because of impressive corporate performance, experts say.

Rather, it's the company's holdings in China and Japan that are fuelling its heady stock move, they tell The New York Times.

Yahoo's share of U.S. digital ad revenue fell to 5.8 percent last year from 6.8 percent in 2012, eMarketer estimates.

Editor’s Note: 18.79% Annual Returns . . . for Life?

But Yahoo has a 24 percent stake in China's Alibaba, which combines the functions of Amazon, eBay, PayPal and even a little Google. And Yahoo has a 35 percent stake in Yahoo Japan.

"In the United States, they are doing the best they can, and I think [CEO] Marissa Mayer is doing a fine job, but their core business is challenged, to be polite, and it will likely remain that way for some time," Victor Anthony, managing director for Internet media at Topeka Capital Markets, tells The Times.

"For Yahoo, it’s all about Asia."

Yahoo shares closed Tuesday at $39.52. Anthony believes the company is worth $50 to $52 a share, with $30 of that coming from Alibaba, $10 from Yahoo in the United States and $7 from Yahoo Japan.

The rest comes from share buybacks, which are financed largely with revenue from the Asian holdings, he says.

As for the company outside of its Asian holdings, "Yahoo may be able to turn around its core business, but the divide between possible and probable is wide," Morningstar analyst Rick Summer writes on Morningstar's website.

"We believe the company can improve its near-term fortunes, but Yahoo's longer-term positioning and durability of its advantages are unclear.

Editor’s Note: 18.79% Annual Returns . . . for Life?

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