(Bloomberg) — In a month during which the red-hot trade in technology stocks has wavered and options activity dominated headlines, traders just got jolted with a spike of trading volume.

Equity transactions surged Friday amid a quarterly event known as quadruple witching, when options and futures on indexes and equities expire. During the first 15 minutes of trading, volume on S&P 500 stocks was double the average for that time of day over the past 30 sessions as the benchmark fell 0.3%.

The event is getting more attention than usual because options activity from small investors and the so-called Nasdaq whale have been blamed for whipping up turbulence in internet and software shares. Despite an 11% drop in the Nasdaq 100 from its Sept. 2 peak, open interest on bullish contracts tied to the gauge remains elevated. So are calls linked to shares of tech titans like Apple Inc. and

Read More