# Lynx ATS Enumerations

Lynx is an alternative trading system (ATS) or dark pool operated by Cboe Global Markets in Canada.

The following fields have Enumerations:

* AGGRESSOR_SIDE - Indicates whether a trade resulted from an incoming buy or sell order.
* BOOK_TYPE - Type of order book or trading mechanism through which a trade was executed.
* BYPASS - Identifies whether the trade resulted from a Bypass order
* MKT_PHASE - Indicates the instrument’s current market phase, as specified by the trading venue
* ODD_LOT - Indicates whether a trade was an odd lot
* ORDER_TYPE - Type of order.
* REASON_CODE - Reason for an instrument status update
* SPECIAL_TERMS - Indicates any non-standard settlement / execution terms associated with a trade
* TRADE_PERIOD - Market period during which a trade was executed.
* TRADE_TYPE - Type of trade
* UPDATE_TYPE - Type of update

#### AGGRESSOR_SIDE - Enumeration

| Enumeration ID   | Enumeration Description                          |
|------------------|--------------------------------------------------|
| ‘””’             | Undefined (e.g. off-book trades, auction trades) |
| B                | Buy                                              |
| S                | Sell                                             |

#### BOOK_TYPE - Enumeration

|   Enumeration ID | Enumeration Description   |
|------------------|---------------------------|
|                0 | Lit order book            |
|                1 | Off-book                  |
|                2 | Dark book                 |
|                3 | Odd lot book              |
|                4 | Special terms book        |

#### BYPASS - Enumeration

| Enumeration ID   | Enumeration Description   |
|------------------|---------------------------|
| ‘””’             | Not a bypass trade        |
| Y                | Bypass trade              |

#### MKT_PHASE - Enumeration

| Enumeration ID   | Enumeration Description                  |
|------------------|------------------------------------------|
| B                | Market-wide circuit breaker              |
| C                | End of transmission                      |
| E                | End of system hours                      |
| H                | Halted                                   |
| M                | End of market hours                      |
| O                | Start of messages                        |
| Q                | Start of market hours                    |
| R                | Resume after market-wide circuit breaker |
| S                | Start of system hours                    |
| T                | Trading                                  |

#### ODD_LOT - Enumeration

| Enumeration ID   | Enumeration Description   |
|------------------|---------------------------|
| ‘””’             | Board lot                 |
| Y                | Odd lot                   |

#### ORDER_TYPE - Enumeration

| Enumeration ID   | Enumeration Description   |
|------------------|---------------------------|
| L                | Limit Order               |

#### REASON_CODE - Enumeration

| Enumeration ID   | Enumeration Description   |
|------------------|---------------------------|
| ‘””’             | Unspecified               |
| B                | Business halt             |
| R                | Regulatory halt           |

#### SPECIAL_TERMS - Enumeration

| Enumeration ID   | Enumeration Description                |
|------------------|----------------------------------------|
| ‘””’             | No special terms (standard settlement) |
| C                | Cash                                   |
| DD               | Delayed delivery                       |
| ND               | Next day                               |

#### TRADE_PERIOD - Enumeration

| Enumeration ID   | Enumeration Description   |
|------------------|---------------------------|
| -                | Regular trading           |
| I                | Intraday auction          |

#### TRADE_TYPE - Enumeration

| Enumeration ID   | Enumeration Description   |
|------------------|---------------------------|
| ‘””’             | Regular trade             |
| D                | Derivative-related cross  |
| H                | Hidden order execution    |
| I                | Internal cross            |
| M                | Intentional cross         |
| m                | Midpoint trade            |

#### UPDATE_TYPE - Enumeration

| Enumeration ID   | Enumeration Description   |
|------------------|---------------------------|
| A                | Add                       |
| D                | Delete                    |
| F                | Fill                      |
| M                | Modify                    |
| P                | Partial fill              |