How about BitUSD? your logic is that The only logical way to bet is to assume everyone else will eventually bet with consensus toward USD. But why? Can BitUSD exchange with USD at a fixed rate? or who make BitUSD tie to USD will be rewarded? No. Actually there is no link between BitUSD and USD except the name, the only way to win is to forsee the price trend of BitUSD correctly, no matter how the BitUSD/USD rate will change. Isnt it absurd to suppose that the market will make one thing tie to USD only because you name it *USD?
However things like market making can make this tie happen, and then can lead BitUSD to act like USD in payment and deposits, then Bitshare system will be more meaningful then Bitcoin
Actually, it isn't absurd to suppose that it will track simply because of the name. To demonstrate why, let me introduce the following principles:
0) BitShares have non-0 value
1) USD has non-0 value
2) There exists a ratio between the value of BitShares and USD known to the market.
3) All trades are voluntary
4) All new issuance is based upon a short and a long taking opposite sides
5) Both the short and long have financial incentive to ensure they enter the position at the current exchange rate.
As a result all short positions are by definition at a price that reflects the proper ratio or the trade would not have occurred.
Once the trade has occurred the market participants must agree on all subsequent trades.
When the owner of BitUSD wishes to sell, he must find a buyer. He of course wants to sell it for as high a price as possible while everyone else wants to buy for as low a price (in BitShares) as possible. No one would dare pay more than the USD / BitShare exchange ratio and no one would sell for less than the exchange ratio.
The short position has constant pressure to cover because of the carrying cost, while the long position is receiving twice the dividends per unit value and thus there is an ample market to buy his BitUSD because excluding exchange rate risk, BitUSD pays twice the return as BitShares.
So BitUSD is a prediction market on what the future resale value of BitUSD in terms of BitShares will be.
Sure, the promise of delivery is one aspect of futures contracts, but if you look closely, 99% of future contracts are never delivered and in fact the total outstanding futures contracts often exceed the available supply of a given commodity. The future market would be just as valuable if all trades were settled for USD rather than delivery because, in theory, the USD received would allow the commodity to be bought for immediately delivery.
Try a thought experiment, assuming you had 1000 BitShares today, at what ratio would you short BitUSD and at what ratio would you buy BitUSD.... you now have your bid-ask spread.