US stock markets set for a rough open as quad witching hits

S&P 500 futures are down 48 points or 0.85%, which is near the pre-market low. The usual mix of tariff worries is weighing but there are also technical factors in the mix with a notional $4.7 trillion in options expiring today.
Quad witching are days when there is the expiration of:
- stock index futures
- stock index options
- stock options
- and single stock futures
Increasingly these products are the tail that wags the dog.