Whisky Tango Foxtrot, Over?

So, there is a theory in finance called rational market hypothesis. The theory, to oversimplify slightly, says that a price of a publicly-traded security represents a rational analysis of all the known fundamental factors that effect the price.

If this is so, how on God's green Earth do you explain the last two day's stock market? Yesterday, bonds (specifically Treasury bonds) were downgraded, so the market sold stocks and bought bonds! Today, with no significant additional information, the stock market goes up 3.98%! Rational my ass - this is shear blind stupid panic!