<p>At Cryptsy the order is First In First Out influenced by the account's trading history. If the server were to receive buy orders at the same time assuming there is enough coins at the specified price to fill the orders, the server looks at each account and the one with the most trading history gets processed first, then in order to the account with the least trading history. I work for Cryptsy, I'm Brad! </p>

CC BY-SA 3.0
2014-04-08T18:44:40.480Z
2014-04-08T18:44:40.480Z
Cryptsy_Brad
<p>According to <a href="https://bitcoin.stackexchange.com/a/20759/14400">this answer</a> it allocates according to rule #1 - First Some First Serve.</p>

CC BY-SA 3.0
2014-03-31T18:41:52.993Z
So much "First Come, First Served", actually, that occassionally I've placed a buy order some satoshis below the topmost sell price and get it served with 2 different events at 2 prices, even though the total amount of coins offered at top sell price has not been depleted.
Joe Pineda
CC BY-SA 3.0
2014-03-31T01:56:21.900Z
2014-03-31T01:56:21.900Z
2017-04-13T12:47:36.647Z
CoinsKillTheFed
<p>How does cryptsy.com allocate trades for many orders with same price ?</p>

<p>Orders can come from one or many accounts, my question applies to both situations, but it's obviously more interesting how they are executed when orders come from multiple accounts from different people. For example, if I see order for 100 BTC and want to attach my order for 0.1 BTC to the same price tag, what are my chances of getting a deal ? Do I get a deal only after all 100BTC exchanged ?</p>

<p>Obvously my question applies to both types: buy and sell orders.</p>

<p>Do other exchanges have same order allocation schema as Cryptsy ? If not, what allocation schemas do they use ?</p>

<p>Examples of possible allocations that I can think of:</p>

<p>1) First Come First Serve - earliest order gets deal first</p>

<p>2) Last Come First Serve - latest order gets deal first</p>

<p>3) Proportional - deal amount is distributed between orders proportional to amount of these orders.</p>

<p>4) Minimal split - system picks closest amount to avoid splitting orders into many small fractions.</p>

<p>5) Small orders first, Large Last - close as many orders as possible to keep minimum number of open orders in the system.</p>

<p>6) Each account gets equal share from new deal regardless of order size or time</p>

<p>7) Random per account - equal probability for each participating account to get a deal</p>

<p>8) Random per order - gives incentive to make many smaller orders rather than one large order</p>

CC BY-SA 3.0
2014-03-31T04:53:03.277Z
possible duplicate of [How do buy and sell orders work?](http://bitcoin.stackexchange.com/questions/20752/how-do-buy-and-sell-orders-work)
dchapes
CC BY-SA 3.0
2014-03-31T18:35:13.107Z
No exchange could ever use #2, it'd give an unfair advantage to those entering at last minute - high frequency trading only, no humans allowed! Numbers 3, 7 and 8 would still favor last-minute traders, though less than #2. #4 or 6 seem to me the only ones to be fair appart from #1
Joe Pineda
CC BY-SA 3.0
2014-04-01T13:05:17.060Z
While I have done no research whatsoever to prove it, I am pretty sure that only FIFO, 1) is used. Everything else is way more complicated and/or easy to game.
Murch
<exchanges><exchange-rate><trade><exchange-order><cryptsy>
How does cryptsy.com allocate trades for many orders with same price
CoinsKillTheFed
# How does cryptsy.com allocate trades for many orders with same price

(Asked by: username_0 on 2014-03-30)

How does cryptsy.com allocate trades for many orders with same price ?

Orders can come from one or many accounts, my question applies to both situations, but it's obviously more interesting how they are executed when orders come from multiple accounts from different people. For example, if I see order for 100 BTC and want to attach my order for 0.1 BTC to the same price tag, what are my chances of getting a deal ? Do I get a deal only after all 100BTC exchanged ?

Obvously my question applies to both types: buy and sell orders.

Do other exchanges have same order allocation schema as Cryptsy ? If not, what allocation schemas do they use ?

Examples of possible allocations that I can think of:

1) First Come First Serve - earliest order gets deal first

2) Last Come First Serve - latest order gets deal first

3) Proportional - deal amount is distributed between orders proportional to amount of these orders.

4) Minimal split - system picks closest amount to avoid splitting orders into many small fractions.

5) Small orders first, Large Last - close as many orders as possible to keep minimum number of open orders in the system.

6) Each account gets equal share from new deal regardless of order size or time

7) Random per account - equal probability for each participating account to get a deal

8) Random per order - gives incentive to make many smaller orders rather than one large order

**Tags:** exchanges, exchange-rate, trade, exchange-order, cryptsy

> **Comments:**
> **username_1**: possible duplicate of [How do buy and sell orders work?](http://bitcoin.stackexchange.com/questions/20752/how-do-buy-and-sell-orders-work)  
> **username_2**: No exchange could ever use #2, it'd give an unfair advantage to those entering at last minute - high frequency trading only, no humans allowed! Numbers 3, 7 and 8 would still favor last-minute traders, though less than #2. #4 or 6 seem to me the only ones to be fair appart from #1  
> **username_3**: While I have done no research whatsoever to prove it, I am pretty sure that only FIFO, 1) is used. Everything else is way more complicated and/or easy to game.  

---

## 2 answers

### Answer by username_4 on 2014-04-08. Score: 3 | Accepted answer

At Cryptsy the order is First In First Out influenced by the account's trading history. If the server were to receive buy orders at the same time assuming there is enough coins at the specified price to fill the orders, the server looks at each account and the one with the most trading history gets processed first, then in order to the account with the least trading history. I work for Cryptsy, I'm Brad!


---

### Answer by username_0 on 2014-03-31. Score: 1

According to [this answer](https://bitcoin.stackexchange.com/a/20759/14400) it allocates according to rule #1 - First Some First Serve.

> **Comments:**
> **username_2**: So much "First Come, First Served", actually, that occassionally I've placed a buy order some satoshis below the topmost sell price and get it served with 2 different events at 2 prices, even though the total amount of coins offered at top sell price has not been depleted.  

---

