Re:"MS stock price went up significantly after they posted their results last week."
...and then promptly sank back the next day. Probably when the herd of speculators noticed profits had actually fallen substantially after accounting for deferred revenue.
I'm actually surprised they didn't drop further. Some of that deferred revenue was Win7 sales MS wanted to book as Win8, use of the $14.99 upgrade voucher magically converting the sale into a full price Win8 sale with bragging rights attached. The silence from MS tells me that didn't work, that MS couldn't even fake Win8 sales.
Investors apparently haven't noticed that yet, more accurately most haven't. But the more volatile the stock gets the more gamblers will flock to exploit it and todays news could easily signal the start of the stampede.