What happened

Major U.S. market indexes shot higher in early trading Tuesday, rebounding from the markets' massive sell-off Monday. But other countries have stocks, too, and one of those other countries is Russia. And Russian stocks are rocking today!

Shares of three of the Russian stocks best known to U.S. investors -- internet search engine Yandex (YNDX), telecom star Veon (VEON -1.75%), and steel producer Mechel PAO (MTL) -- were all up more than 10% in early trading. And as of 11:50 a.m. EDT, Yandex was still up 4.8%, Veon 3.2%, and Mechel 5%.

Map of Russia with icons representing money and oil

Image source: Getty Images.

So what

Why did these stocks go up so far, so fast? (And why are they coming down a bit as the day stretches on?)

The first question is easy to answer: Lots of stocks went up this morning, as short traders closed short positions to lock in profits, and value hunters raced into the market to scoop up what looked like bargains at the time.

But those apparent bargains may not actually have been real bargains. As I review the numbers today, the S&P 500 is still trading at more than 20 times trailing earnings, which remains a historically high valuation. Yandex shares in particular cost more than 37 times earnings. Veon's a lot cheaper at under six times earnings, but it carries a boatload of debt -- more than $9 billion net of cash on hand.

And Mechel, which sells for a seemingly ridiculous 1.2 times trailing profits, has 13 times more debt on its books than its own market capitalization.

Now what

In short, none of these three Russian stocks are gimmes at current prices, even after suffering along with the rest of the market on Monday. At the same time, other than simply being part of a broad market rebound, none of the stocks had any good news of their own to report today.

Actually, the contrary might be true. Russia is now engaged in what appears to be an oil-price war with Saudi Arabia (in addition to a few actual wars in countries such as Ukraine and Syria). That's bad news for energy companies. I think it also makes Russia a bit riskier than the average country to invest in today.

If I'm right, this would explain why, after shooting so high early in the morning, Yandex, Veon, and Mechel are already tempering their gains.