Cramer's lightning round: Sell Mallinckrodt after its 'nutty' acquisition of Acthar
Mallinckrodt Plc. : "Sell, sell, sell. They paid too much for Acthar. I don't know why they did that. It was kind of a nutty thing to do. We're going to say no."

Alteryx Inc. : "I want you to let it run. I just hear nothing but good things about that. It's a small-cap stock that's going to the big time. Keep it."

Charles River Laboratories Intl. Inc. : "People thought the quarter wasn't that good. We should get [CEO] Jim Foster back on. I thought the quarter was OK. This is like Idexx Labs and like Henry Schein . Periodically, you get a quarter and people think it's not that great, but I like that company."

GoPro Inc. : "I thought GoPro would have a better quarter. I still think it might be OK, but boy, they did throw cold water on the whole darned situation in that last conference call."