What are the Index Historical Charts? The SpotGamma Historical Chart reflects how the S&P 500 has behaved over time relative to three of our strongest proprietary metrics: Our Call Wall, Put Wall, and Volatility Trigger. The y-axis reflects the value of the SpotGamma key levels while the x-axis reflects the trading date. To best visualize the activity over time, you can click and drag a smaller timescale and the chart will zoom in on your preferred viewing pane. Statistically, over time, the price of the indices and ETFs usually stay within the Call Wall and the Put Wall. When looking at times where the price of indices are below the Vol Trigger, we expect higher volatility, and when above the Vol Trigger, we expect lower volatility. Tracking the market relative to SpotGamma levels, and pairing these with our estimated short term expected moves of 1-day and 5-day, you can get a good sense of how the market has behaved statistically over time and factor these insights into your trading approach. SpotGamma Subscribers can access this chart for the SPX, SPY, NDX, QQQ, RUT and IWM. Related articles What is the Price Vs 2M/6M Realized Volatility index chart? What is the Options Risk Reversal index chart? Call Wall What is the Options Clearing Corporation (OCC) Indicator? What is included in each SpotGamma subscription level?