Market Maker Reference
This specification defines the ticker format for weather prediction markets. Use this as the authoritative reference for ticker generation and parsing.
Overview
Weather prediction market tickers follow a standard Gemini format for temperature threshold contracts:
Code
Ticker Structure
| Component | Description | Example |
|---|---|---|
GEMI | Gemini prediction market prefix | GEMI |
Event | Event type + location + expiry datetime | WXHIGH-MIA-2603260359 |
Contract | Temperature threshold condition | LO76 |
Full Ticker Example:
GEMI-WXHIGH-MIA-2603260359-LO76
Event Format
The event identifies the weather event type, location, and expiry datetime.
Structure
Code
Components
| Component | Format | Description |
|---|---|---|
TYPE | WXHIGH | Weather event type |
LOCATION | [A-Z]{3} | Location code for the weather station |
YYMMDDHHmm | [0-9]{10} | Expiry datetime in UTC (2-digit year, month, day, hour, minute) |
Expiry Datetime Format
Code
| Position | Part | Description |
|---|---|---|
| 1-2 | YY | Year (e.g., 26 for 2026) |
| 3-4 | MM | Month (01-12) |
| 5-6 | DD | Day (01-31) |
| 7-8 | HH | Hour in UTC (00-23) |
| 9-10 | mm | Minute in UTC (00-59) |
Examples:
2603260359= March 26, 2026 at 03:59 UTC2601010359= January 1, 2026 at 03:59 UTC2507150359= July 15, 2025 at 03:59 UTC
Supported Event Types
| Event Type | Code | Description |
|---|---|---|
| Highest Temperature | WXHIGH | Highest recorded temperature for the day at the specified location |
| Lowest Temperature | WXLOW | Lowest recorded temperature for the day at the specified location |
Event Type Availability
Additional weather event types may be added. Check the API Reference for the current list of available markets.
Supported Locations
Weather contracts use Gemini-specific location codes to identify weather stations. These location codes are different from airport codes or NWS Weather Forecast Office (WFO) codes, although resolution data is sourced from the National Weather Service (NWS).
| Location Code | Weather Station | City | State |
|---|---|---|---|
NYC | Central Park | New York City | NY |
MDW | Chicago Midway | Chicago | IL |
MIA | Miami International Airport | Miami | FL |
LAX | Los Angeles International Airport | Los Angeles | CA |
BOS | Boston (Logan Airport) | Boston | MA |
Location Availability
Additional locations may be added. Check the API Reference for the current list of available locations.
Contract Format
Weather contracts support three threshold types based on temperature in degrees Fahrenheit. All boundaries are inclusive.
Contract Types
| Type | Format | Description | Example |
|---|---|---|---|
| Less than or equal to | LO{TEMP} | Temperature will be ≤ the specified value | LO76 |
| Range | {TEMP1}TO{TEMP2} | Temperature will be between the two values (inclusive) | 44TO45 |
| Greater than or equal to | HI{TEMP} | Temperature will be ≥ the specified value | HI55 |
Components
| Component | Description |
|---|---|
LO | Less than or equal to (≤) indicator |
HI | Greater than or equal to (≥) indicator |
TO | Range delimiter (inclusive on both ends) |
TEMP | Temperature in whole degrees Fahrenheit |
Temperature Encoding
Temperatures are encoded as whole integers representing degrees Fahrenheit.
| Temperature | Encoded |
|---|---|
| 76°F or below | LO76 |
| Between 44°F and 45°F | 44TO45 |
| 55°F or above | HI55 |
| 90°F or above | HI90 |
| 32°F or below | LO32 |
Complete Examples
Miami – High Temperature ≤ 76°F
Highest temperature at Miami 76°F or below, expiring March 26, 2025 at 03:59 UTC
| Component | Value |
|---|---|
| Prefix | GEMI |
| Event Type | WXHIGH |
| Location | MIA |
| Expiry Datetime | 2503260359 |
| Contract | LO76 |
| Full Ticker | GEMI-WXHIGH-MIA-2503260359-LO76 |
New York City – High Temperature Range
Highest temperature at New York City between 44°F and 45°F, expiring March 26, 2025 at 03:59 UTC
| Component | Value |
|---|---|
| Prefix | GEMI |
| Event Type | WXHIGH |
| Location | NYC |
| Expiry Datetime | 2503260359 |
| Contract | 44TO45 |
| Full Ticker | GEMI-WXHIGH-NYC-2503260359-44TO45 |
Chicago – High Temperature ≥ 55°F
Highest temperature at Chicago 55°F or above, expiring April 10, 2025 at 03:59 UTC
| Component | Value |
|---|---|
| Prefix | GEMI |
| Event Type | WXHIGH |
| Location | MDW |
| Expiry Datetime | 2504100359 |
| Contract | HI55 |
| Full Ticker | GEMI-WXHIGH-MDW-2504100359-HI55 |
Los Angeles – High Temperature ≥ 90°F
Highest temperature at Los Angeles 90°F or above, expiring July 15, 2025 at 03:59 UTC
| Component | Value |
|---|---|
| Prefix | GEMI |
| Event Type | WXHIGH |
| Location | LAX |
| Expiry Datetime | 2507150359 |
| Contract | HI90 |
| Full Ticker | GEMI-WXHIGH-LAX-2507150359-HI90 |
Boston – High Temperature ≤ 32°F
Highest temperature at Boston 32°F or below, expiring January 15, 2026 at 03:59 UTC
| Component | Value |
|---|---|
| Prefix | GEMI |
| Event Type | WXHIGH |
| Location | BOS |
| Expiry Datetime | 2601150359 |
| Contract | LO32 |
| Full Ticker | GEMI-WXHIGH-BOS-2601150359-LO32 |
Regex Patterns
Full Ticker
Code
Capture Groups:
- Event type (e.g.,
WXHIGH) - Location code (e.g.,
MIA) - Expiry datetime (YYMMDDHHmm)
- Contract (e.g.,
LO76,44TO45,HI55)
Event Only
Code
Capture Groups:
- Event type
- Location code
- Expiry datetime (YYMMDDHHmm)
Contract Only
Code
Validation Rules
- Ticker must start with
GEMI- - Event type must be a supported weather event type
- Location must be a supported location code
- Expiry datetime must be a valid UTC datetime in
YYMMDDHHmmformat - Contract must be one of:
LO{TEMP},{TEMP1}TO{TEMP2}, orHI{TEMP} - Temperatures must be whole integers
Changelog
| Version | Effective Date | Changes |
|---|---|---|
| 1.0 | 2026-03-27 | Initial specification |