A position in options (a situation/ relationship expressed originally as vega) in which any increase in the implied volatility of the underlying asset will generate a profit, even without a move in the underlying asset. For example, in a long calendar, the position is long vega when an investor longs farther out options and short front month options. Therefore, as implied volatility moves up, the position makes money and as volatility falls, it loses money, all else being the same.