NEW YORK (TheStreet) -- The S&P 500 and Dow Jones Industrial Average both closed at all-time highs.
On CNBC's "Fast Money" TV show, Guy Adami, managing director of stockmonster.com, said Twitter (TWTR) might have a small pullback but suggested investors definitely not short the stock.
Axiom Capital's Gordon Johnson added that TWTR is very overvalued compared to Facebook (FB). He said not to short TWTR now, but to look for an opportune time to do so.
Jim Lebenthal, CFO and CIO of Lebenthal & Company, said he wouldn't get long or short TWTR at current levels.
Jon Najarian, co-founder of optionmonster.com and trademonster.com, said there is a shortage of stock available for TWTR, helping to drive the price higher. He can't justify owning it at current levels.
Ben Kallo, senior research analyst at RW Baird, was a guest on the show. He said Chinese demand for Tesla Motors' (TSLA) Model S is not an issue but production and charging proponents are. He'd rather be in solar stocks such as SunPower (SPWR) and SolarCity (SCTY) in 2014.
Adami suggested investors who bought the dip in TSLA should take profits now. Johnson said he is a seller of Trina Solar (TSL).
Turning to mobile, Lebenthal said T-Mobile U.S. (TMUS) is unlikely to go much higher, even in an M&A situation, because it's gone up so much already this year. He added that at some point antitrust issues will become a concern within the rapidly consolidating industry.
Najarian said BlackBerry (BBRY) could continue to go lower. Adami concurred.