Carl Icahn is seen being interviewed at 'David Moore's Funny Business Show.' - 

This final note on the way out, which comes with the observation that it's been a busy day for what're commonly called "activist investors."

First, a guy named Bill Ackman, who runs a hedge fund called Pershing Square Capital Management, was squeezed off the board of JCPenney this morning. It's a kind of inside baseball thing involving who's gonna actually run the struggling retailer, but it does get me to the juicy bit of today's activist shareholder news.

Carl Icahn -- activist-shareholder extraordinaire -- tweeted this this afternoon:






Icahn apparently wants the company to buy back more of its stock, which -- on the news that Icahn's in the game -- rose almost 5 percent today.



Follow Kai Ryssdal at @kairyssdal