Quote from: Bitcoinfan on August 08, 2015, 01:54:52 AM
#b) the Unlocking Limit. As a result, the market will be frozen to any trades. To be able to trade within the market, a trader must offer a price that brings #c) percentage change (absolute value) lower than 3.5%. In other words, this trader must offer a price better than $270 - $290, or else his trade won't go through. $270 because in absolute value terms its still abs(-3.5%).
Since everyone else will be frozen out of the market, unless they can offer a better bid/ask that will bring the absolute value %percentage change lower, in this situation the incentives are offered so that someone will be able to profit if purchased BTC at a lower price. They are guaranteed a checkpoint to cash out. If someone offers a price higher that does not bring the last transacted price %change lower, then the trade is rejected by the code. Speculators have to trade within this declining %percentage window, which gets incrementally smaller with each trade.
Quote from: cdetrio on October 05, 2015, 04:57:45 PM
The person who buys at the lower price will only be able to profit if they can sell later to someone else. That's not an arbitrage opportunity, so actually there's no guarantee of a checkpoint to cash out. The person who buys at the lower price is taking on risk and betting that more speculators will come in the future (more may not come, so the window may or may not get smaller).
Every speculator trades in expectation that they will profit in the future. The mere statement that a person who buys in this LMSR pegged market is taking a risk that will speculators may not come occurs in every other single market as well. When you buy your house, your speculating that you will be able to sell it for a higher value than when you purchased. But there are numerous occasions when a person was unable to sell. Price is only the last trade that buyers and sellers agreed.
Its true when locked that the LMSR-pegged market can be driven by the offsetting trader who got in before. But it also allows for outside traders to come in, only if their trade moves to reduce the locking limit. An outside trader may want to chase the locking limit because its a moving target from which they can profit from later in time if it is still locked.
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Quote from: cdetrio on October 05, 2015, 04:57:45 PM
The person who buys at the lower price will only be able to profit if they can sell later to someone else. That's not an arbitrage opportunity, so actually there's no guarantee of a checkpoint to cash out. The person who buys at the lower price is taking on risk and betting that more speculators will come in the future (more may not come, so the window may or may not get smaller).
What drives expiring contracts to converge on the spot price is delivery arbitrage. In the non-expiring scheme you describe, there is no delivery arbitrage, and thus no real reason for the price to converge to the peg. In that aspect, it is similar to the first version of BitUSD, which relied on self-fulfilling expectations to drive the peg. The later version of the peg mechanism is based on a repurchase agreement. The repurchase agreement incentivizes sellers to come back later and place bids; without it, potential buyers would always be wondering whether or not they'll be the last buyers.
This is a fair critique. I don't believe its the same as Bitshares's BitUSD in the same sense a self-fufilling expectation is needed to drive the beg. There is an expectation of fulfillment here, but there is also that fulfillment of delivery (which I am loosely interpreting as profit). So the two, bitshares and LMSR-pegged are distinctly different. In bitshares one had to hope that another trader would bail them out. But here that trader can take actions (if they are on the right side of the trade) to unwind their position. An eligible trader would be guaranteed settlement of their trades, and profit from when they first purchased. That is the same as saying there is a guaranteed delivery, however it is only for a eligible few. More speculators are not needed, only the ones that are already speculating. Why else are they in the market? To make money? Well they are guaranteed a profit here.
A rational trader will take the arbitrage opportunity, because they are the few guaranteed it, and may not have that chance in the future. No one would take the risk indefinitely and leave their money in. Else they wouldn't be there in the first place.