On 6 November 2025, the Singapore Exchange Regulation (“SGX RegCo“) issued the consultation paper on “New Trading Functionalities and Enhancements for SGX Securities Market” (“Consultation Paper“). The consultation period ends on 31 December 2025.
SGX RegCo plans to replace its current securities trading system, SGX REACH ST, with a new trading engine, “Iris-ST”. Iris-ST will introduce new and improved features concerning, among other things, order types and risk controls. SGX RegCo invites feedback on the proposals in the Consultation Paper which covers amendments to the SGX-ST Trading Rules (“SGX-ST Rules“), CDP Clearing Rules, SGX-ST Mainboard Rules and SGX-ST Catalist Rules to implement these new changes. Iris-ST is expected to be implemented in H2 of 2027.
Some of the key changes include:
- Implementation details of new auction price collars: On each trading day, auction routines are held: (a) before trading commences to determine the opening price for the day; (b) at the end of the mid-day break to determine the opening price for the afternoon trading phase; and (c) at the close of trading to determine the closing price for the day. Participants of a market may enter orders during the auction routine. Auction routines are also used to determine the opening price following an order management phase, which is imposed, for example, upon the lifting of a suspension or trading halt (“Adjust Phase”). SGX RegCo proposes to enhance the auction routines by implementing auction price collars to prevent extreme price dislocations while enabling price discovery. Details of the new auction price collars being consulted on include: (i) scope of instruments subject to the auction price collar; (ii) auction price collar thresholds for exchange traded funds (ETFs); (iii) treatment of resting orders priced outside the auction price collars; and (iv) exceptions to the application of auction price collars.
- Revisions to non‑cancel phase: An auction routine comprises: (a) a pre-open or pre-close phase, during which order entry, amendments, and withdrawals can be made; and (b) a non-cancel phase, during which: (i) no order entry, amendment or withdrawal is allowed, (ii) orders are matched, and (iii) the equilibrium price (“EP“) is determined. Currently, the non-cancel phase occurs simultaneously with the end of the pre-open or pre-close phase (which happens randomly at any time within the space of a minute). SGX RegCo seeks views on: (1) extending the duration of the non‑cancel phase and allowing order entry during that phase, but continuing to disallow the amendments to and withdrawals of orders; and (2) the preferred duration for the revised non-cancel phase for the opening routine, mid‑day break, closing routine and Adjust Phase.
- Unmasking of “market by order” (MBO) data: During the auction routines, a participant may subscribe for SGX’s market data, including the market by order (“MBO”) data which is order information (e.g. price, volume, queue positions) on all the individual orders in the order book. Currently, MBO data does not show the full information of market orders or of individual bid and ask orders that are at prices better than the indicative equilibrium price (“IEP”). SGX RegCo proposes that, in line with international practice, the MBO data from Iris-ST will include order information for all individual orders in the order book even if they are market orders or at prices better than the IEP.
- New pre-trade risk control system: SGX RegCo proposes to offer a pre-trade risk control system in Iris-ST which the SGX-ST trading members or clearing members that qualify as a trading member may use to fulfil their obligations to adopt adequate and appropriate policies and controls to manage risks arising from order acceptance, execution and settlement.
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