The European Union's record $5 billion fine against Google, levied Wednesday morning, marks the biggest regulatory attack yet on technology giants. But investors and analysts largely shrugged off the ruling's potential to immediately dent Google's business.

The real damage will hinge on how aggressively the EU cracks down on Google's lucrative agreements with smartphone-makers and carriers going forward — and how quickly Google rivals like Amazon and Microsoft pounce. Amazon and Samsung Electronics, a Google partner, have already started pushing into web search with their voice-activated products.

As expected, the European Commission declared Google's conduct with its Android mobile operating system anti-competitive and ordered the company to cease its behavior, suggesting it change its contracts with phone-makers. That targets Android's greatest asset for Google: the way it distributes its lucrative services, such as search, its web browser and its app store, to more than a billion devices. The European ruling took direct aim at those three services.