Bitcoin Forum

I have a simple question to the experienced traders here:

is there a general rule across the exchanges as of the order in which orders at the same price are are executed when they are matched?

I noticed that when I placed a buy order on bitstamp it was the best one. Then more orders where placed at the same price. When the price was met by sellers my order was executed last. So it obviously is not relevant placing an order first (at least at stamp).

bumping for ideas.
anyone?

Yes, sometimes funny things are going on.
In a podcast about bitcoin exchanges it was said that there are many exchanges with stealth and with phantom orders. There are also rumors that bitcoin exchanges get liquidity from mining pools. As I understood it, bitcoin exchanges sell the bitcoins that mining pools did mine.

Using http://www.orderbook.info (http://www.orderbook.info) and filters I observed that bitstamp and coinsetter often show the same side / size / price triples - actually the price varies a tiny bit. On bitfinex some orders disappear and re-appear just some seconds later.

Typically Exchanges execute orders at price, then time priority. So your order should have been filled before any subsequent orders.
Were you looking at the public market data to determine who came first? or looking at Bitstamp's acknowledgement of your order?

Specifically with Bitstamp, we've seen that there is a lag between the time your order is acknowledged as Submitted to when it appears on their orderbook. What may have happened is that the orders that were executed before yours were actually sent in before as well.

The order of events might have been:

1. Other market participants send orders at price $400
2. You send in your order for the same price
3. Your order is acknowledged by Bitstamp
4. Other orders appear on public order book
5. Your order appears on public order book
6. All orders are executed in Time Priority, yours is filled last