By Marco BösingWhat Is OpEx?
OpEx stands for Options Expiration — the date on which options contracts expire. On this day, open options are either exercised, closed out, or expire worthless. The most significant OpEx dates are the monthly expiration (third Friday of the month) and the quarterly Triple/Quadruple Witching, when options, futures, and index options expire simultaneously.
Around OpEx dates, markets regularly experience heightened volatility and unusual price behavior. Market makers and hedgers must adjust their positions (gamma exposure), which often triggers rapid, sharp moves in both directions. After expiration, market structure frequently normalizes and new trends can establish themselves.
For active traders, understanding the OpEx cycle is essential for correctly interpreting these price behavior anomalies and avoiding being caught on the wrong side of the market.