US STOCKS-Wall St to open modestly higher; on pace for 6-day run
* 'Quadruple witching' may boost volume, volatility
* Oracle slumps in premarket after results
* Carmax surges in premarket after earnings
* Futures up: Dow 25 pts, S&P 3.75 pts, Nasdaq 4.75 pts (Updates prices)
By Chuck Mikolajczak
NEW YORK, June 20 (Reuters) - U.S. stock index futures pointed to a modestly higher open on Friday, putting the S&P on track to extend its record high with a sixth straight day of gains, and a fourth weekly gain over the past five.
* Investors may see a spike of volume and volatility at the open and towards the closing bell as Friday marks a "quadruple witching" day - the expiration of stock options, index options, index futures and single-stock futures - as traders close hedging positions or roll them over at the last minute.
* Oracle Corp shares were down 6.3 percent to $39.82 before the opening bell after it posted fourth-quarter results that disappointed investors looking for more progress against rivals selling web-based services.
* Five days of gains in the benchmark S&P index marked its longest winning streak since mid-April. For the week, the index is up 1.2 percent, while the Dow is up 0.9 percent and the Nasdaq has gained 1.1 percent. Continuación...