US STOCKS-Indexes set to open lower as crude prices drag
* Crude oil prices resume sliding
* Investors prepare for "quadruple witching"
* Red Hat up after FY rev forecast increase
* Futures down: Dow 33 pts, S&P 4.25 pts, Nasdaq 2.5 pts (Adds details, comment; updates prices)
By Abhiram Nandakumar
Dec 18 (Reuters) - U.S. stock indexes were set to open lower on Friday as a selloff in commodity markets showed no signs of easing.
Trading could be more volatile than usual on "quadruple-witching" Friday, when options on stocks and indexes as well as futures on indexes and single stocks expire.
Crude oil prices were heading for their third straight weekly loss as global oversupply continued to pile pressure. Exxon and Chevron shares were down less than 1 percent in premarket trading.
"Everyone is worried about the $1.2 trillion options expiration that takes place today and you're going to see some jimmying and jammying around that," said Jeffrey Saut, chief investment strategist at Raymond James Financial in Florida. Continuación...