A number of options and futures contracts on stocks and stock-indexes are set to simultaneously expire Friday in an occurrence known as quadruple witching

U.S. stock futures wavered Friday ahead of the simultaneous expiration of an array of stock futures and options contracts that could result in increased volatility.
Futures tied to the S&P 500 wavered between losses and gains. The benchmark may still be on track to eke out a tepid gain for the week, despite two consecutive days of declines. Contracts tied to the tech-heavy Nasdaq Composite ticked up 0.3%.