It's called variance swapsQuote from Maverick74:
I've seen guys get really creative and turn a simple position into a 30 legged monster all because they are trying to "harvest" theta. I honestly think you would be better off selling straddles if you are trying to harvest theta. I've never seen these 20 legged spreads work out.

Quote from stevenpaul:
I was reading the interview with Tony Saliba in Schwager's __Market Wizards__ about how Saliba would "string together" butterflies to create a broad profit zone. I can manage to produce nice, broad profit zones with calendar spreads (at the cost of excessively long vega exposure), but trying to string together butterflies seems to be impossible. There's always that deep risk zone between the the profit zones. Is it indeed possible to create a seamless profit zone with flies, comparable to that of a multi-calendar spread position, and if so, could we get a little discussion going about it?
Thanks for your feedback, folks.
Quote from Joao Fiore:
It's possible to combine two broken wing butterflies to widen the profit zone by choosing the strikes correctly.
Here is a pretty good video by a hedge fund manager, Rob Chastain, speaking to a group for ThinkOrSwim that uses that technique:
http://www.youtube.com/watch?v=o0OFGNnNtg8&feature=BF&list=PLBD245E33D18BCE88&index=3
The first part is a wrap up of a Q&A on futures, then the options' part begins.
Good luck!
Joao
Quote from sonoma:
I thought that might be the case. Have you looked at trying to string them together through the life of a trade?
I don't want my comments to seem as if there is any mystery in all this. My suggestion was to compare what you've considered with an alternative. I'm suggesting you simply adhere to the principle of shorting centrally and buying laterally. For instance, if you start with an ATM fly, as the underlying moves, you pick a point at which you admit your initial assumption was incorrect and then move the short option, which will have moved ITM, more centrally. You do this by buying a fly on the relevant side. Your overall inventory is now better positioned with your market view, centered around the underlying. There are some other subtleties, but this type of adjustment is what I would mean as "stringing them together." You can't put on an initial position with flys or calendars "linked" together and arrive at the same p/l.Quote from stevenpaul:
I haven't tried doing that, but in view of the posts by you and MushinSeeker, who suggested the same concept, I am going to try it out on paper. I imagine it's a whole art in itself to leg into a portfolio of butterflies to create an optimal position. As Maverick74 was pointing out earlier, such byzantine positions can quickly spiral out of control, but done with appropriate restraint, I imagine there's some potential. Would you indulge us with some specifics of how you've played this strategy, if you've had occasion to put on flies in this way?