NEW YORK (TheStreet) -- TheStreet's Jim Cramer said Alcoa (AA) isn't the Alcoa you want to invest in right now.

Speaking from the floor of the New York Stock Exchange, he told a viewer contacting him Wednesday via Twitter that investors will want Alcoa after its merger with RTI International Metals  (RTI) goes through so Alcoa expands beyond just aluminum. You're not going to get a pop in this stock otherwise. The Alcoa he likes is the future company, not the present version of it.

Another viewer noted that after reaching $90 a share, Shake Shack  (SHAK) looks like it's heading down to $60. What does Cramer think? He said he he likes it for the long term because he believes in founder Danny Meyer and thinks the burgers are terrific.

However, he urged investors to realize the stock is overvalued when compared to other burger chains like Jack in the Box  (JACK) and McDonald's  (MCD).

As for the viewer who is long BlackBerry (BBRY), Cramer recommended going back and listening to the company's conference call, which he said was one of the worst of the year. Management seemed unable to explain how the company made its software revenue, and afterwards the company stressed that it was not for sale and would not be able to stem its losses in hardware, which Cramer said makes it a disaster.

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