About Omega ATS

An overview of Omega ATS

Omega ATS is a fully automated order matching and trade execution marketplace for equities and listed fixed income. This lit, protected auction market, based on strict price/broker/time, offers an inverted pricing model.



Limit orders are executed at the price (or better) specified in the order. All orders adding liquidity are placed on the book at the price in the order.

Fill or Kill

If the order can not be completely filled immediately, it is cancelled instead of being placed on the book.

All or None

The Omega ATS accepts All-or-None order requests but they are treated as a Fill or Kill.

Bypass Intentional and Internal Cross

Subscribers can submit a Bypass Cross for free. If the cross is not marked Bypass, the order will be rejected. Subscribers must displace visible liquidity up to the desired price prior for crossing. All Bypass Crosses will have priority over posted liquidity and will not be subject to interference at the displaced price.


Day orders are effective during normal market hours. Subscribers with open orders at market close will receive “done for day” messages informing the originator that any open orders have been closed.

Immediate or Cancel

The Omega ATS matches as many shares as possible and any balance is cancelled.

Iceberg Order

Iceberg orders allow subscribers to enter the full amount of their order while only exposing a portion of their order on the public book. The minimum displayed portion is one board lot.

Hidden Mid-Point Peg Functionality

Mid-point peg orders are hidden orders thar are pegged to the mid-point of the Protected Canadian Best Bid and Offer (CBBOP).


‘Post Only’

Subscribers can submit Execution Instructions that specify orders are to be ‘posted’ to the book. Orders flagged as Post Only are not eligible to remove liquidity from the order book. If an order marked Post Only is immediately executable (i.e., it can remove liquidity from the order book), it is instead rejected.

If a subscriber enters an order without post-only instruction, it is matched against the Omega ATS at the best price. If unable to match, the order is placed on the Omega ATS book and presented to the market via the Omega ATS data feed. Price improvement, if available, is given to orders that remove liquidity from the book.


Orders marked as bypass do not interact with hidden liquidity and will only interact with visible liquidity. Bypass orders must be Immediate or Cancel orders.


The Omega ATS offers our subscribers the choice to attribute their orders or remain anonymous when posting to the order book or executing trades. By default, orders are attributed, but this may be turned off via a FIX tag.

Self Trade Prevention

The Omega ATS offers the ability to prevent orders originating from the same broker, trade desk or trader from interacting to prevent unintended wash trades. Either the passive or active order can be set to reject in the event of a potential wash trade.

Cancel on Disconnect

By default, all order entry connections are set to cancel on disconnect unless otherwise specified by the subscriber or vendor. When an order entry session disconnects, whether intentionally or unintentionally, the Omega ATS will cancel any open orders from the connection.

Order Protection

Direct Action Order (DAO)

This marker is used by a broker dealer or their trader to indicate that the order has satisfied all checks for book through/trade through prevention before reaching the marketplace and will not require the marketplace to check for OPR compliance. To use this marker, the session must either be defaulted to DAO, or the order must have FIX tag 6820 = N.

OPR Cancel

OPR Cancel – If an order is designated to be OPR Cancel, the Omega ATS will fill as much of the order as possible up to the far side of the CBBO. The remainder of the order would be canceled to prevent trade through or book through. To use this option, the session must either be defaulted to OPR Cancel, or the order must have FIX tags 6820 = Y and 6821 = N.

OPR Re-Price

If an order is designated to be OPR re-priced in the event it would either trade through or book through the CBBO, the Omega ATS will fill as much of the order as possible up to the far side of the CBBO. The remainder of the order would then be re-priced one tick away from the far side to prevent locking the CBBO. To use this option, the session must either be defaulted to OPR Re-price, or the order must have FIX tags 6820 = Y and 6821 = Y.

Marketplace Information

Market Regulation

The Investment Industry Regulatory Organization of Canada (“IIROC”) provides market surveillance. The Omega ATS provides a streaming data feed to IIROC allowing the status and trading of all equity symbols to be monitored through the IIROC interface.

Trading halts imposed by the TSX are co-ordinated with Omega ATS by IIROC. Regulatory halts (and resumptions) are enforced solely at IIROC’s discretion. IIROC is also responsible for the triggering of market-wide and single stock circuit breakers. When a halt or circuit breaker is implemented on Omega ATS, all open orders in the affected securities are cancelled.

Tick Increments

Orders submitted below $0.50 can trade and quote in half penny increments and orders submitted at or above $0.50 can trade and quote in full penny increments.

Trading Increments

Trading occurs in industry standard board lot increments based on the previous day’s closing price:
$1.00 and up – 100 shares
Between $0.10 and $1.00 – 500 shares
Under $0.10 – 1000 shares

Order Priority Queue

With the exception of Bypass Internal Cross which has priority over posted liquidity and no interference, the Omega ATS order book follows Canadian industry-standard price/broker/time priority rules.