This is the position Tony Saliba used to make his money in the eighties. Back then, however, vol surfaces were less efficiently priced.
I would think that if you did a basket of these and hedged out long vega risk by selling index vol you will start to approach a dispersion position. Problem is that 1. you will need to sell a ton of index vol to compensate you for the theta you are paying and this will cause pain when vol goes up. 2. you will need to scale your book up a lot to make enough return to make it interesting for you.
I bet the upward sloping termstructure also makes this annoying from a carry perspective.
I would think that if you did a basket of these and hedged out long vega risk by selling index vol you will start to approach a dispersion position. Problem is that 1. you will need to sell a ton of index vol to compensate you for the theta you are paying and this will cause pain when vol goes up. 2. you will need to scale your book up a lot to make enough return to make it interesting for you.
I bet the upward sloping termstructure also makes this annoying from a carry perspective.
