Options Trading, Options Greeks, Volatility Trading, Moontower, Black Scholes Model.
vega decreases (red dashed line) causing the call spread vega (green dashed line) to increase from its initial value. As vol declines your vol length is increasing. Whoa again, this looks like negative gamma with respect to vol! Ratio Trade. Short ATM option, long extra OTM options. (Vega neutral,