70 lines
2.3 KiB
Markdown
70 lines
2.3 KiB
Markdown
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BSIP: 0032
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Title: Always Match Orders At Maker Price
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Author: Abit More <https://github.com/abitmore>
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Status: Draft
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Type: Protocol
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Created: 2018-02-16
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Discussion: https://github.com/bitshares/bitshares-core/issues/338
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Replaces: -
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Worker: To be done
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# Abstract
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Currently, under most circumstances, when matching two orders, the maker price
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will be used. That said, the order that is placed earlier sets a price,
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another order that is placed later accepts the price, thus a match, two orders
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pay to each other at that price. For example, if one person (A) placed a limit
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order to sell 100 BTS at 0.1 USD per BTS, another person (B) then placed a new
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limit order to buy 100 BTS at 0.105 USD per BTS, the two orders will match at
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0.1 USD per BTS, so A will pay 100 BTS and get 10 USD, B will pay 10 USD and
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get 100 BTS.
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However, when matching a taker limit order with a maker margin call order,
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the taker price is being used. For example, if trader A's margin call order is
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selling 100 BTS at no less than 0.1 USD per BTS, then trader B placed an order
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that buys 100 BTS at 0.105 USD per BTS, the two order will match at 0.105 USD
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per BTS, so A will pay 100 BTS and get 10.5 USD, B will pay 10.5 USD and get
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100 BTS.
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This BSIP proposes a mechanism to change this behavior: always match orders
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at maker price.
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# Motivation
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Make the exchange system more user-friendly.
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# Rational
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To attract more users, the system should be fair.
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It's common sense that orders should be matched at maker price.
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# Specifications
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There is a parameter in price feed named MSSR, which stands for "maximum short
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squeeze ratio". Maker price of margin call orders is MSSP, which stands for
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"maximum short squeeze price", is calculated as `feed_price / ( 100% + MSSR )`.
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Note: `feed_price` here is in terms of debt/collateral, aka "how much debt per
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collateral".
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Matching between a limit order and a call order is done in
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`check_call_orders(...)` function of `database` class, price of limit order
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is always used. It need to be changed to use MSSP when the call order is maker.
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# Discussion
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[to be added if any]
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# Summary for Shareholders
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[to be added if any]
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# Copyright
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This document is placed in the public domain.
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# See Also
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* https://github.com/bitshares/bitshares-core/issues/338
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* https://bitsharestalk.org/index.php?topic=25926.0
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