The 10-year US Treasury yield rose to approximately 4.8%, Brent crude oil broke through $92, and expectations of a September rate hike intensified, putting downward pressure on US stock valuations from both the discount rate and financing costs perspectives. Technology stocks with longer durations were more significantly impacted. On September 1st, the S&P 500 opened 0.66% lower, and the SPY subsequently fell below the key options position zone around $765. Cboe research points out that if market makers are generally in a negative Gamma state, their hedging behavior will manifest as buying on rallies and selling on declines, thus amplifying existing market movements.
