Jim Cramer answers viewers' Twitter (TWTR) questions from the floor of the New York Stock Exchange. He reveals his thoughts on AK Steel (AKS), which he calls a 'casualty of the euro.' Cramer says that despite the company's urges for him to rethink his stance, he maintains that he is negative on AK Steel. When it comes to the run-up in biotech stock Celgene (CELG), Cramer says there's no reason to sell it. He explains that some numbers show that shares of Celgene are still dirt cheap and he recommends that investors continue to buy it. In response to a viewer asking if Fitbit (FIT) can go higher or if it's ready for a pause, Cramer reveals that his target on the stock was $50 and with the stock at about $48, he doesn't want to be greedy. With that in mind, he recommends taking a little off the table when it comes to Fitbit. Cramer also weighs in on Microsoft (MSFT), Salesforce (CRM) and Disney (DIS). If you have a stock question, tweet it @jimcramer using #CramerQ.