Topic: Britcoin V2 Community Input (Read 1088 times)

They would be able to since orders are not filled one to one, but on a fifo bases matching the best orders that completely fill the order, so with enough volume both orders would be filled.

Being able to buy or sell a specific quantity can be a nice feature for those who want it, htough it can probably also be annoying for those who would prefer to be the one choosing the quantity.

For example suppose I am thinking I might like to buy a special deal on alpaca socks but would need no more and no less than 100 BTC to do that. Meanwhile I also am tempted by a collection of phonograph records someone wants no more and no less than 2000 USD for.

I would thus like to buy either 100 BTC or 2000 USD or both, but any less of either is useless (I might as well just use my GBP for whatever I normally use it for and forget about those socks and recordings.)

While it is nice for me to place an order for no more nor less than 100 BTC, I can see if being potentially irritating for other people who might wish they could sell me some smaller quantity.

-MarkM-

But rates are not quotes, what you calculate might not be valid once you actually get around to placing the order.

IMO third option is the best one.

Right now it's hard to see at what rate you are selling the coins at, what you could do is that you use the same system as you do now, but add an "resulting in X BTC per GBP".

But really, it is much easier to just specify the rate you want to buy BTC or GBP at, if you want to find out how much BTC or GBP you get from the trade you can just whip out good ol calculator and do "X BTC(or GBP) * rate" which i think more people are used to than the current "X BTC(or GBP)/Y GPB(or BTC)" method.

There are a couple of design decisions to be made when creating an exchange.

The first is how to internally account for trades.

I have come up with 3 separate methods which each have their own advantages and disadvanatages.

The first scheme is the way britcoin operates currently, what I have/what I want pairs.  This allows for a very simple representation and a very simple interface for users.

This scheme results in rounding when calculating the rate at which the trade has been placed, this is unavoidable when using this representation.
There is again potential for rounding when multiplying quantity*rate.
This scheme results in 2 separate instances of rounding where others result in a single instance.

The second scheme is to store quantity/rate/have_currency/want_currency.  This is closer to the normal forex market place, but allows for buying or selling a precise amount of either side of the trade.
This results in rounding both when calculating quantity*rate and when matching 2 buy orders for inverse currency pairs (1/rate).

The third scheme is the normal forex method, in which you have the currency pair/rate/quantity/buy or sell. There is no way to buy/sell a specific quantity of the base currency with this scheme.
This results in rounding when calculating quantity*rate.


So which method do people prefer?