Ackman out at JCPenney, Icahn investing in Apple?

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.