FIX API Reference Data

Participants may download a list of the instruments available (or reference data about them) to trade on Polymarket US by submitting a SecurityListRequest [x] message.

Table 23: SecurityListRequest (x) message

Tag	Name	Req	Type	Description
< Standard Header >		Y		35 = x
320	SecurityReqID	Y	String	Unique ID associated with this request.
336	TradingSessionID	N	String	Used to filter for instruments by market state (CLOSED, OPEN, PREOPEN, SUSPENDED, EXPIRED, TERMINATED, HALTED, MATCH_AND_CLOSE_AUCTION)
559	SecurityListRequestType	Y	int	The type of request being made (0=Individual symbol, 4=All Securities)
55	Symbol	C	String	Required if SecurityListRequestType (559) = 0 (individual security)
< Standard Trailer >		Y

Example 21: Request for information on all securities

8=FIXT.1.1 | 9=75 | 35=x | 49=SENDER | 56=TARGET | 34=12 | 52=20240516-14:28:38 | 320=REF-DATA-001 | 559=4 | 10=048 |

Upon receipt, Polymarket US will respond with a SecurityList [y] message containing the requested information. Note that the content provided by the SecurityList [y] message does not differ depending on whether an individual symbol was listed versus all securities.

Table 24: SecurityList (y) message

Tag	Name	Req	Type	Description
< Standard Header >		Y		35 = y
320	SecurityReqID	Y	String	The unique SecurityReqID (320) sent on the request.
322	SecurityResponseID	Y	String	Unique ID for this response. Typically a 13 character alphanumeric string.
560	SecurityRequestResult	Y	int	The status of the request (0=Valid, 1=Invalid/unsupported, 3=Not authorized)
146	NoRelatedSym	C	NumInGroup	Number of instruments to be returned. Only present for valid requests.
→ 55	Symbol	Y	String	Instrument symbol
→ 48	SecurityID	Y	String	Will always equal Symbol (55)
→ 22	SecurityIDSource	Y	int	8 = Exchange symbol
→ 167	SecurityType	N	String	EVENT=Event contract. Currently, Polymarket only offers EVENT instruments.
→ 231	ContractMultiplier	N	float	The ratio or multiplier to convert from “nominal” units (e.g. contracts) to total units (e.g. shares). Applicable for Fixed Income, Derivatives, etc.
→ 864	NoEvents	Y	NumInGroup	Number of repeating EventType entries. Will always be 1.
→→ 865	EventType	Y	int	Code to represent the type of event (5=Activation)
→→ 866	EventDate	Y	LocalMktDate	Date that the instrument first started (or will start) trading on the exchange in YYYYMMDD format.
→→ 868	EventText	Y	String	Event string. Always ‘StartDate’.
→ 969	MinPriceIncrement	Y	float	Minimum price increment (tick size)
→ 1151	SecurityGroup	Y	String	The name of the group of securities to which this instrument belongs.
→ 562	MinTradeVol	Y	Qty	The minimum quantity allowed on an order. This field can be a decimal, indicating the ability to trade fractional shares of this instrument.
→ 15	Currency	Y	Currency	Currency for the instrument.
< Standard Trailer >		Y

Example 22: SecurityList [y] indicating two securities (color-coded)

8=FIXT.1.1 | 9=336 | 35=y | 34=9 | 49=TARGET | 52=20240516-14:28:38.864954771 | 56=SENDER | 146=2 | 55=GC-Dec-2030 | 48=GC-Dec-2030 | 22=8 | 167=NONE | 231=1 | 864=1 | 865=5 | 866=19700101 | 868=StartDate | 969=0.01 | 1151=GC | 562=1 | 15=USD | 55=GOOG | 48=GOOG | 22=8 | 167=NONE | 231=1 | 864=1 | 865=5 | 866=19700101 | 868=StartDate | 969=0.01 | 1151=Equities | 562=1 | 15=USD | 320=2007026312 | 322=1HPT7F2AA6404 | 560=0 | 10=007 |

Overview

Protocol Specification

FIX Order Entry

FIX Market Data

FIX Drop Copy

Table 23: SecurityListRequest (x) message

Table 24: SecurityList (y) message

Figure 16: Request form security reference data

​Table 23: SecurityListRequest (x) message

​Table 24: SecurityList (y) message

​Figure 16: Request form security reference data

Table 23: SecurityListRequest (x) message

Table 24: SecurityList (y) message

Figure 16: Request form security reference data