What's the best position/spread to achieve positive gamma but with vega neutrality. In essence, one expects the market to make a good size move but fears that the move may not be accompanied by an increase in volatility, thus making the long straddle/long strangle an unacceptable option since the long straddle/long strangle is along gamma and long vega. So a position is needed that will benefit from market movement via positive gamma, but is neutral to implied volatility via vega neutrality. What spread will achieve this? Thank you.