Breakingviews: Ackman's Chipotle recipe outdated

Breakingviews
Kevin Allison
WATCH LIVE
Chipotle restaurant workers in Miami
Getty Images

Bill Ackman may be reaching deep into the activist investor cookbook to find a recipe to revive Chipotle. The pushy hedge-fund manager's firm Pershing Square reported a 10 percent stake in the struggling burrito chain on Tuesday. He is no stranger to the fast-food business, but there are few obvious parallels to his previous investments in Burger King, McDonald's or .