It's not just Yahoo! (Nasdaq: YHOO) that's smarting this morning.

Now that Microsoft (Nasdaq: MSFT) has pulled itself out of its one-man race for Yahoo!, some of Yahoo!'s ballyhooed Asian investments are feeling the pain., China's leading business-to-business website, closed 6% lower today. South Korea's Gmarket (Nasdaq: GMKT) traded as much as 3% lower this morning. Yahoo! Japan was spared -- for now -- since today is a trading holiday in Japan.

Yahoo! has a minority stake in all three companies. Why are they declining? Wasn't Alibaba threatening to wrestle away Yahoo!'s stake in the company if there was a transfer of ownership to Microsoft?

There are two theories. The first is that Yahoo! may be forced to take drastic action to appease its own shareholders, and that could take the form of selling its positions to raise cash or spinning off its Asian investments. The more reasonable theory is that even if these were minority stakes within the Yahoo! portfolio, having the wealthier Microsoft as a sugar daddy could have presented the companies with broader strategic opportunities if not outright buyouts.

The timing isn't great. Alibaba shares have shed 63% of their value since peaking after last year's IPO. Yahoo! Japan last week suffered its biggest drop in more than two years after posting disappointing financial results. Gmarket is the only one riding favorable momentum after topping analyst expectations last week, but it's also Yahoo!'s smallest investment of the three.

Yahoo! can't seem to catch a break. It has been counting on its Asian investments to help offset its iffy fundamentals domestically. Asia was supposed to provide a mattress -- at one time valued at nearly $12 a share -- but now that mattress has holes.

Bad news for Yahoo!'s Asian investments can only be interpreted as good news for their rivals. (Nasdaq: BIDU), attempting to take on Alibaba's Taobao with its own consumer auction site, was up sharply this morning. Chinese portals like SINA (Nasdaq: SINA) and (Nasdaq: NTES) also opened higher, either as a sigh of relief that Microsoft won't attempt to get bigger in China or perhaps because of speculation that Microsoft will try to assemble its own portfolio of Asian investments.

Either way, when Microhoo sneezes, the germs and opportunities are carrying over to the other end of the world.

Microsoft is an Inside Value recommendation. SINA is a Stock Advisor selection. Baidu, Gmarket, and NetEase are Rule Breakers picks. You don't need to go on a treasure-hunting adventure to unearth any or all of the Fool's newsletter services. Thirty-day trial subscriptions are available.

Longtime Fool contributor Rick Munarriz is a fan of Yahoo! and Microsoft but not of bad weddings. He does not own shares in any of the stocks in this story. Rick is part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Fool has a disclosure policy.