Microsoft is stepping up as the most valuable company in the world. Apple was in that spot and became the first company worth more than $1,000,000,000,000 this fall. Amazon soon became the second. But both companies have seen significant declines in their stock prices. Apple has lost more than $300,000,000,000 in value over concerns about slowing iPhone sales. Amazon's stock fell because of a poorer-than-expected earnings report in October. Meanwhile, Microsoft's value is rising because investors like that it caters to businesses more than consumers. Microsoft's value is now at $828,100,000,000 ... about $1,000,000,000 more than Apple's current value.