Editing 0x (section)

== 2.3. Matches are unenforcible ==

A standard limit-based order book works by sorting all the sell orders from lowest to highest and all the buy orders from highest to lowest. The sell orders can then be put next to the buy orders to tell traders the bid-ask spread - a measure of the difference between the lowest price a seller is willing to sell at and the highest price a buyer is willing to buy at.

The bid-ask spread is useful because it can be used to ensure traders get access to accurate pricing information, knowledge of liquidity, and so fourth. But pricing information in 0x cannot be determined because matching is unenforcible. A person may indicate to a matching server they are after a certain trade but there is no part of the protocol that determines whether they go through with it.

This means that pricing cannot be determined since all open orders in the order book cannot be matched. Another consequence of this is that traders can never be ensured that they will get the best possible price for an order because they cannot be guaranteed to match against the tip of the order book.

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