What happened

Shares of Yandex (NASDAQ:YNDX), the "Russian Google," closed down 9.2% on Wednesday, after Reuters  reported that Russia's biggest internet portal is expanding even farther away from its core business. Yandex, which inked a deal giving it control over Uber's Russian operations last year, is acquiring a "start-up fuel delivery service" known as Toplivo v Bak ("fuel into the tank").

When summoned by smartphone, Toplivo v Bak travels to a customer's car and adds fuel to its gas tank -- or at least that's its current model. Yandex says the company will now cease providing this service and focus on providing fuel to Yandex's own Yandex.Drive fleet.

Cartoon figures looking at stock chart fallen through floor

Why is Yandex stock down so much today? That's a real head-scratcher. Image source: Getty Images.

So what

Investors don't seem too keen on the idea, selling off Yandex stock in response to the news. Still, it's worth noting that there's svery little news for them to be reacting to. According to Reuters, Yandex did not disclose how much it would be paying to acquire Toplivo v Bak, or just how big its new subsidiary is in terms of revenue or profit.

For that matter, there is so far no mention of the deal whatsoever on Yandex's investor-relations page, nor any filing  with the SEC that might shed further light on the details of this acquisition.

Now what

Long story short, investors don't know either the costs of this deal, or the potential benefits. If you ask me, there's therefore little reason for people to be selling the stock on this news -- or to be buying it, for that matter.

Rich Smith has no position in any of the stocks mentioned. The Motley Fool recommends Yandex. The Motley Fool has a disclosure policy.