FIX PROTOCOLAN INTRODUCTION TO THE FIX PROTOCOL

AGENDA

FIX General Overview.

FIX in Detail.

Session layer.

Application Layer.

FIX engine.

FIX versions.

What is FIX?

Financial information eXchange.

Protocol created by Fidelity and Salomon 1992.

A standard way to communicate trading information electronically

between brokers, buy-side institutions, and markets.

An industry driven messaging standard for the exchange of trading

related information between financial institutions.

Platform independent.

Flexible.

Open (free) protocol.

Growth of FIX

Began as IOI (Indication of Interest) - Bid/Offers.

Moved to Orders and Executions:

Actual Orders to buy and sell shares in securities, and responses from

the counterparty about how those Orders were executed.

FIX has become the most commonly used protocol for electronic

financial transactions.

Used by – ECNs, Brokers, Portfolio Managers, Exchanges.

Covers major asset classes – Equities, Derivatives, FX, Fixed Income.

Supports Pre-Trade, Trade, and Post-Trade messaging.

What is a FIX message?

FIX message contains three parts:

- Header

- Body

- Trailer

FIX message is a collection of fields e.g. Symbol, Order ID, Price,

Order Quantity.

Each field is a tag-value pair. <tag>=<value> e.g. 55=IBM.

Two types of FIX messages:

- Application Level

- Session Level

What do you mean by tag value pair?

Tag:

FIX uses predefined Tags.

Each Tag represents a specific Field.

Each Tag is given a predefined number.

FIX dictionary provides the list of Fields and corresponding Tag numbers.

Value:

Values represent the value the Tag is assigned to.

Supported data types are: int, float, Qty, Price, char, Boolean (Y/N), Currency, timestamp, string.

e.g. Symbol is tag55. If there was a FIX order for Intel, it would look like

55=INTC

What are the parts of a FIX message?

Three parts:

Header – contains administrative information about the message – who

sent the message, who the message is going to, what time it was sent.

Body – contains the actual financial information – fields like Symbol,

Shares, Price.

Trailer – usually there is only one field set in here – the Checksum for

the message – to ensure message integrity.

Message Header

All administrative fields:

Who sent the message.

Who the message was sent to.

Who was the trader that sent the message (if applicable).

What version of FIX is being used in the message.

What type of message it is.

Where the message is to be routed to (if applicable).

Mandatory FIX 4.2 Header Fields

Tag Field Name Req’d Comments

8 BeginString Y Identifies beginning of new message and protocol version. Always the first field in message.

9 BodyLength Y Message length in bytes, forward to the Checksum field. Always second field in message

35 MsgType Y Defines message type. Always third field in message.

49 SenderCompID Y Assigned value used to identify firm sending message.

56 TargetCompID Y Assigned value used to identify receiving firm.

34 MsgSeqNum Y Integer message sequence number.

52 SendingTime Y Time of message transmission (GMT).

Header Field Examples

8=FIX 4.2 Message is using Version 4.2 of FIX protocol (BeginString).

52=20090724-13:40:24 What time the message was sent (GMT) (SendingTime).

49=Fidelity Fidelity is sending the message, specified in the header using the SenderCompID field.

56=ML Message being sent to Merril Lynch, specified in the TargetCompID field.

35=D Fidelity sending Merril Lynch an Order, specified in the MsgType field.

D signifies an Order. Other values for MsgType include:

- 8 (Execution Report).

- 6 (Indication of Interest).

- A (FIX logon message).

Message Body

The Body of a FIX message contains the actual financial information that will be important to the receiver of the message.

Important fields that could be in the body of a FIX Order message are:

• Symbol (tag 55).

• Order Quantity (tag 38).

• Order Type (tag 40).

• Price (tag 44).

• Side (tag 54).

• TimeInForce (tag 59).

Message Body Example

I want to create an order to buy 10000 shares of Yahoo at the Market, and have it be Good Till Cancelled.

OrderQty – 10000 38=10000

Symbol – Yahoo 55=YHOO

Order Type – Market Order 40=1 (1 indicates Market Order).

Time In Force – Good until cancelled 59=1 (1 indicates Good Until cancelled).

Side – buy 54=1 (1 indicates buy).

Message Trailer

The Trailer of a FIX message usually contains only one field – tag 10 the CheckSum.

The Checksum in a FIX message provides a simple message integrity check. The Checksum is the sum of all the binary values in the message. E.g. 10=193

Upon receiving a message, a FIX engine will compute the checksum of the message, and make sure it matches the checksum in the actual message, this helps to identify transmission problems.

Example FIX messages

A FIX 4.2 message that would be seen in a FIX engine log file for an

Order for 10000 shares of IBM.

8=FIX4.2|9=0132|35=D|57=Simulator|34=2|49=SLGM0|56=SB10|52=20100315-

13:45:28|55=IBM|40=2|38=1000|21=2|11=order 0|60=20100315-17:45:20|54=1|

44=110.5|10=097

The message fields are delimited using the ASCII 01 <start of header>

character.

Tag 8 FIX version Tag 55 Symbol

Tag 49 SenderCompID Tag 54 Side

Tag 35 MessageType Tag 38 OrderQty

Two types of FIX messages

Application level message.

Session level message.

Both are constructed the same way (tag/value pairs) but the functionality of

the two types is different.

An application level message contains the actual financial data that a user will care about.

Application level messages include Orders, Execution Reports, Indications of Interest, Order Cancels, Allocations.

Session level messages are used for administrative functionality, and connectivity between FIX engines,

Session level messages include – FIX Login messages (establish a connection to a remote FIX engine), FIX Logoff messages, FIX Resend Request messages.

Session Layer

A session layer of any protocol defines how two sides using that

protocol communicate.

The FIX session layer handles all the administrative functionality

of the FIX protocol.

Session layer – handles communication between the two

counterparties, and also makes sure that no messages are

missed, and bad messages are rejected.

What type of messages are in the FIX Session Layer?

Session level messages:

Logon (35=A) – handshake to authenticate counterparty.

Resend Requests (35=2) - used to request missed messages after detecting a message gap

Heartbeats (35=0) /Test Requests (35=1) - keep alive packets used to detect problems during slow message traffic periods.

Reject (35=3)

Sequence Reset (35=4)

Logout (35=5)

What is a sequence number?

The FIX protocol also specifies the use of Sequence numbers in the

Session layer for all FIX messages.

It is a unique identifier for each incoming and outgoing message, and is

used by the FIX engine to keep track of how many messages have

come in and gone out.

It is an incrementing number.

Normally, at the beginning of a trading day, the first message sent out

by both sides would be sequence number 1, and would increase by one

every time a new message is sent out.

Sequence numbers are unique for each connection, and for each

incoming and outgoing message.

So how does it all get started?

The side that has agreed to initiate the connection (the Initiator) first

makes a socket connection to the counterparty’s FIX engine and then

sends a FIX Logon message.

Upon receiving that FIX Logon message, the Acceptor counterparty

must acknowledge that FIX Logon message with its own FIX Logon

acknowledgement message.

Once the ack has been received, the connection has been established

and trading can begin.

Sample FIX Message – Logon and Logon Ack

PGB10 PXY11

8=FIX4.2|9=0060|35=A|34=1|49=PGB10|56=PXY11|52=20090713-14:48:20|98=0|108=30|10=008

8=FIX4.2|9=0060|35=A|34=1|49=PXY11|56=PGB10|52=20090713-14:48:21|98=0|108=30|10=009

Application Layer

Contains the actual useful financial data.

e.g. Orders, Execution Reports, Indications of Interest, Allocations,

Quotes, Cancel Requests.

e.g. How do I create an Order in FIX 4.2

FIX. 4.2 specifies these fields are required:

Client Order ID, Handling Instructions, Symbol, Side, Transaction Time,

Order Quantity, Order Type.

Application Layer

ClOrdID (tag 11) (Client Order ID) is a unique identifier for any order.

HandlInst (tag 21) (Handling Instructions ) allows you to specify

whether you want this order to be automatically executed or want

broker intervention.

Symbol (tag 55) – the stock symbol for that security.

Side (tag 54) – represents whether or not stock is being bought (1) or

sold (2).

TransactTime (tag 60) – time the order was created by the trader or

trading system.

OrderQty (tag 38) – the number of shares in that order.

OrderType (tag 40) – type of order.

FIX Customer / Broker Example: Step 1: Customer A’s Order

BrokerBroker

Customer ACustomer A

Accept SellAccept Sell10001000

Cheung KongCheung Kong

FIX Order Accept (Execution Report)

Symbol = 0001.HK

Side = Sell

OrderQty = 1000, OrdType = Market

OrdStatus = New

[35=8;55=0001.HK;54=2;38=1000;40=1;39=0]

FIX Order

Symbol = 0001.HK, Side = Sell, OrderQty = 1000, OrdType = Market

[35=D;55=0001.HK;54=2;38=1000;40=1]SellSell10001000

Cheung KongCheung Kong

Step 2 - Sending an IOI

FIX Network

Broker/Broker/Position TraderPosition Trader

Seller ofSeller of10001000

Cheung Cheung KongKong

CustomersCustomers

FIX IOI

Symbol = 0001.HK

Side = Sell

IOIShares = 1000

Price = 101

IOINaturalFlag = Y

[35=6;55=0001.HK;54=2;27=1000;44=101;130=Y;]

Step 3 - Filter IOIs, Cust B’s Order

Broker/Broker/Sales TraderSales Trader

Buy 1000Buy 1000Cheung KongCheung Kong

FIX Order

Symbol = 0001.HK

Side = Buy

OrderQty = 1000

OrdType = Market

[35=D;55=0001.HK;54=1;38=1000;40=1]

Customer BCustomer BAccept Buy 1000Accept Buy 1000

Cheung KongCheung Kong

FIX Order Accept (Execution Report)

Symbol = 0001.HK

Side = Buy

OrderQty = 1000, OrdType = Market

OrdStatus = New

[35=8;55=0001.HK;54=1;38=1000;40=1;39=0]

Step 4 - Traded, Execution Rpts

BrokerBrokerSales TraderSales TraderSold 1000Sold 1000

Cheung KongCheung Kong

Customer BCustomer B

Customer ACustomer A

FIX Execution Report (Filled)

Symbol = 0001.HK, Side = Sell, OrderQty = 1000,

OrdStatus = Filled, LastShares=1000, LastPx=101

[35=8;55=0001.HK;54=2;38=1000;39=2;32=1000;31=101]

Bought 1000Bought 1000Cheung KongCheung Kong

FIX Execution Report (Filled)

Symbol = 0001.HK, Side = Buy, OrderQty = 1000,

OrdStatus = Filled, LastShares=1000, LastPx=101

[35=8;55=0001.HK;54=1;38=1000;39=2;32=1000;31=101]

FIX Engine

A FIX engine is a piece of software that manages

the “FIX session” (external network connection) to counterparties.

- Sequence Number maintenance.

- Resend Requests.

- Establishing, maintaining, and breaking connections.

- Session layer messages – heartbeats, test requests, logons/logoffs.

FIX message formatting and validation (rejection of invalid messages) both inbound and outbound.

FIX Versions

Version: 3.0 4.0 4.1 4.2 4.3 4.4 5.0

Rel. date: Sep95 Jan97 Apr98 Mar00 Apr01 Apr03 Oct06

Business Msgs. 17 20 21 39 61 86 94

Fields: 112 138 208 396 641 914 1139

http://www.fixprotocol.org/specifications/

Version has significant impact on application-level business processing –

messages have different field contents between versions, and are not as a

rule backward compatible.

Trading counterparties must use the same version of the FIX protocol.

Useful Websites

http://www.fixprotocol.org

Central repository & authority for all specification documents.

Discussion forums, presentations.

http://fixglobal.com

FIXGlobal Journal, the FIX Protocol’s official journal.

http://www.fixprotocol.org/FIXimate3.0

FIX interactive message and tag explorer Tool – access and navigate

the FIX specification.