Print Page - Looking for a market maker

Title: Looking for a market maker
Post by: mtgox on July 18, 2010, 11:59:32 AM

I'm looking for someone to act as a market maker on my exchange in order to provide better liquidity. You would have to always hold both a buy and sell order near what you thought the current bitcoin rate should be.
Please email, PM, talk to me if you are interested.
Thanks!

Title: Re: Looking for a market maker
Post by: mtgox on July 19, 2010, 01:20:15 AM

Quote

I'm certainly interested in acting as a market maker. I've been playing around with your site, and the basic functionality seems to be there.

Great send me an email when you get a chance or chat me up in the irc channel.

Quote

Professionalism demands that if someone places an order to buy 100 coins at $0.07 each, the total will be $7.00, not 7.00000000000001

This was just a display bug and is fixed now. Let me know if you notice anything else.

Title: Re: Looking for a market maker
Post by: FreeMoney on July 23, 2010, 11:46:51 AM

Quote from: mtgox on July 19, 2010, 01:20:15 AM

Quote

I'm certainly interested in acting as a market maker. I've been playing around with your site, and the basic functionality seems to be there.

Great send me an email when you get a chance or chat me up in the irc channel.

Quote

Professionalism demands that if someone places an order to buy 100 coins at $0.07 each, the total will be $7.00, not 7.00000000000001

This was just a display bug and is fixed now. Let me know if you notice anything else.

You should do something so that that doesn't happen any where. I just got a long string of 9s in the bitcoins sold field.

Title: Re: Looking for a market maker
Post by: FreeMoney on July 23, 2010, 12:01:32 PM

This is a problem. I got an email saying someone had bought .1BTC for $.061. I don't really mind the tiny trade, but maybe you should throw up a small minimum. The real problem is the my balance now says $.01. Is that my balance? It shouldn't be. But since it says it, it kind of should be.

Title: Re: Looking for a market maker
Post by: mtgox on July 23, 2010, 03:48:34 PM

You are right I'll switch to using decimal arithmetic.

Title: Re: Looking for a market maker
Post by: bitcoinex on July 27, 2010, 11:44:35 AM

I am recommend use the database and its embedded types

postgresql's "numeric" pretty well for me

Title: Re: Looking for a market maker
Post by: theymos on July 27, 2010, 12:23:22 PM

Bitcoin's JSON-RPC deals with floating-point numbers internally, so you need to modify the code to get real precision. Here's a function I wrote to do that:

Code:

std::string taToString(int64 source)
{
	std::string number;
	std::string splitnumber;
	std::stringstream strstream;
	strstream <<source;
	strstream>>number;
	int ti=number.length()-1;
	bool tdone(false);
	while(ti>-1 || tdone==false)
	{
		if(ti==number.length()-9)
		{
			splitnumber="."+splitnumber;
			tdone=true;
		}
		if(splitnumber.length()==0)
		{
			splitnumber=number[ti];
		}
		else if(ti>-1)
		{
			splitnumber=number[ti]+splitnumber;
		}
		if(ti<=-1)
		{
			splitnumber="0"+splitnumber;
		}
		ti--;
	}

	return (splitnumber);
}

Put that in rpc.cpp and replace all instances of nAmount / COIN with taToString(nAmount). Then you'll get a precise string instead of a double.

Bitcoin Forum

Economy => Trading Discussion => Topic started by: mtgox on July 18, 2010, 11:59:32 AM