NEW YORK ( TheStreet) -- Shares of Sony ( SNE) tumbled 7.46% to $18.60 in pre-market trading on Tuesday after the company lowered its financial forecast for the fiscal year ending March 31. Dell ( DELL), however, was one of the tech sector's gainers before market open, as investors responded to Morgan Stanley's decision to upgrade the tech giant to equal weight from under weight. Shares of Dell were up 1.85% to $16.52 in pre-market trading. AOL ( AOL) shares were down in pre-market trading, just a day after the Internet firm announced a $1.1 billion sale of patents to Microsoft ( MSFT). AOL's stock was down 1.33% to $26.05. Microsoft shares were up 0.19% to $31.16. Apple ( APPLE), fresh from hitting yet another new all-time high on Monday, traded up before market open. The iPhone maker's stock was up 0.56% to $639.81. Apple was also one of the Nasdaq's most active pre-market stocks on share volume of 320,333. Sirius XM Radio ( SIRI) was another of the Nasdaq's most active stocks on share volume of 967,378. The satellite radio giant's shares were up 0.22% to $2.32 in pre-market trading. Shares of Internet photo service Shutterfly ( SFLY) were flat, as investors continued to digest Facebook's$1 billion acquisition of rival photo specialist Instagram. Shutterfly's stock closed down more than 4% on Monday after Facebook announced its surprise deal for Instagram. -- Written by James Rogers in New York. >To follow the writer on Twitter, go to http://twitter.com/jamesjrogers. >To submit a news tip, send an email to: email@example.com. Check out our new tech blog, Tech Trends. Follow TheStreet Tech on your wireless devices.