SPX closed Thursday near major resistance backed by 123.7M gamma notional @ 4605/4610, 4560 remains pivot. Notable change: Gamma flip level (the danger zone) moved up 25 points to 4492.5 points. Should we break below this level expect increased volatility. In general: 186.1M in gamma notional is expiring tomorrow which could mess up support/resistance levels and also release a bit of volatility. Minor bearish signal is also the call/put gamma ration which fell to the lowest level of the week (1.60). Happy trading.