Warren Buffett is the CEO of the Berkshire Hathaway (NYSE: BRK.A)(NYSE: BRK.B) holding company, where he helps manage a $287 billion portfolio of stocks, in addition to numerous privately held subsidiaries.

Not even Warren Buffett could get out of the way, Berkshire Hathaway's class A (BRK.A) shares fell 4.1% on the week at $742.901,. But here's where Buffett gets a chance to say, politely, "Told you so.

Such a precipitous increase in the value of U.S. equities has stirred up the usual cacophony of equity-bears screaming “bubble!” “Bubble” is a popular term, but, as it turns out, is rather ill-defined and fuzzy.