Cramer Answers Twitter Questions on Mobileye, Opko Health, Alcoa

Jim Cramer answers viewers' Twitter questions from the floor of the New York Stock Exchange. He reveals why he's getting disappointed in Johnson & Johnson, and why he believes there's a better way to play speculative technologies than through Mobileye. Cramer weighs in on Pfizer's deal with Opko Health, which he says he didn't find that significant. However, he stresses the fact that entrepreneur Phillip Frost continues to buy a lot of shares of Opko is significant, and Cramer continues to be certain that Opko Health is a must-buy. He also explains why Alcoa, which he describes as much more than just a commodities play, is a great multi-year story. Plus, Cramer reveals his thoughts on playing Facebook after the stock's recent run-up.