At expiry, your P&L is determined purely by where the underlying settles relative to your strikes. Before expiry, implied volatility (IV) significantly affects the value of your position through Vega.  

• For long volatility strategies (Long Straddle, Long Strangle): rising IV benefits you, falling IV hurts you.  
• For short volatility strategies (Short Straddle, Short Strangle, Iron Condor): falling IV benefits you, rising IV hurts you.  

The Greeks screen in the strategy detail view shows your current Vega exposure, which quantifies how much your position gains or loses for a 1% change in IV.