US STOCKS-Wall St set to open lower ahead of big tech earnings
* Dollar trading at a three-month high
* IBM down after revenue falls for 13th straight quarter
* Tesla down after UBS downgrades to "sell"
* Apple, Microsoft, Yahoo to report results after the bell
* Futures: Dow down 56 pts, S&P down 2 pts, Nasdaq up 3.5 pts (Adds details, comment, updates prices)
By Tanya Agrawal
July 21 (Reuters) - Wall Street was set to open slightly lower on Tuesday ahead of a raft of earnings from technology giants, including Apple, and as the dollar continues to trade at a three-month high.
The dollar index was down marginally at $97.88, its highest level since April on firming expectation of a U.S. interest rate hike later in the year.
A fall in commodities capped gains on Monday with gold and other precious metals trading near five-year lows. Continuación...