Gamma hedging

Statement:

“A delta hedged portfolio should also be gamma hedged. This ensures that the value of a portfolio consisting of a short option position and a position in the underlying does not change when either delta or volatility changes.”

Is the above statement correct or incorrect

Incorrect and reason:

**Gamma hedging does not ensure hedging against volatility changes. A delta hedged portfolio with a zero gamma can greatly change in value if the volatility changes

My query: does gamma only hedge the delta (non linear volatility) and not the volatility of the underlying.

Why is the statement in correct.

I am unable to link the reason to the statement.


The hedge entails combining the underlying stock position with two options positions in such a manner that both delta and gamma are equal to zero.

My query: does the above mean :

(underlying stock position + delta + gamma =0) or (delta + gamma =0)

Changes in violatility is Vega, so it doens’t really changes the volatility. Gamma hedging protects the changes of delta due to changes in prices. Theta (changes in time), Vega (change in volatitlity).

Gammas measure the sensitivity of delta to a change in the underlying. It’s basically the second derivative of delta. The largest moves for gamma occur when options move quickly towards deltas of 1.0 or 0.0; which means that delta hedges with gamma hedges are hard to maintain because the gammas are so high. I don’t think a gamma hedge would hedge volatility.