Friday will be a quadruple witching day, which could lead to volatility and heavy trading.
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“Witching hours are usually accompanied by considerable volatility in trading volume and stock and derivative prices. As a result, investors can anticipate and plan for the potential effects of these relatively turbulent trading days.
Although index futures and options generally share simultaneous expirations on the third Friday of every month, quadruple witching days only occur on the third Friday of every March, June, September, and December. The last hour of these trading days, from 3 to 4 p.m. EST, is referred to as the quadruple witching hour.
Quadruple witching is similar to triple witching, which only includes the expirations of index futures, index options, and stock options.”