Sellers pay a hedging fee on top of the listing fee a buyer pays for buying product. These funds are used in the hedging pool.Also, a few exchanges are offering short sales on BTC in the near future (about damned time so there is a lot more liquidy and a damned price floor on drops, for fucks sake), so I would be SR will probably start levering out short sales against its long hedge holdings. At least that's what I would be doing.A guy from citigroup has a pretty high-tech btc exchange in beta right now. I'm interested to check it out once it opens to the public, as it will have futures and options from what I'm reading (Then I can do my own hedging!)