MAS Singapore Algo Trading Guidelines

When to Use

Use this skill when gating algorithmic order flow into Singapore Exchange — SGX-ST securities or SGX-DT derivatives — from an entity regulated by the Monetary Authority of Singapore under the Securities and Futures Act 2001 (SFA).

Start here by correcting the most common misconception about this jurisdiction. Singapore has no algorithm registration regime and MAS issues no algorithm identifier. There is no Singapore equivalent of SEBI's exchange-assigned Algo-ID. MAS licenses entities (Capital Markets Services licence or exemption) and registers representatives; SGX registers members and Approved Traders (Futures Trading Rules 2.13.2, 2.13.4). Algorithms themselves are registered nowhere. Any gate that blocks SGX orders for want of a "MAS algorithm registration number" is enforcing a requirement that does not exist.

What does bind a Singapore algorithmic order, and what this skill actually audits:

Entity licensing and the registered human behind the flow — SFA licensing, and the SGX-registered Approved Trader under whose authority the order is entered.
Pre-execution value limits — SGX FTR 3.9.1(3) and Practice Note 3.9.1(3) require Clearing Members to set pre-execution limits on their trading participants, checked either at the Clearing Member's system or by SGX's exchange-hosted Pre-Trade Risk Controls module. The limit values are set by the firm and its Clearing Member.
Forced Order Range — SGX-ST Practice Note 8.6: an order priced outside the range must be confirmed with the Force Key (Regulatory Notice 11.4.2(g)) before it may be submitted.
Circuit breakers — SGX-ST Rule 8.14 with Regulatory Notice 8.14.1 and Practice Note 8.10A; SGX-DT price limits under FTR 4.1.15 and the individual contract specifications.
Automated trading controls — SGX RegCo's Algorithmic Trading Regulatory Guide, key aspects of which were formalised into the Futures Trading Rules and SGX-ST Rules following the SGX RegCo consultation of 21 September 2023.

When NOT to Use

As evidence of a licence or a registration. The engine reads flags the caller supplies. It cannot confirm that a Capital Markets Services licence is live or that an Approved Trader registration is current. The authoritative sources are the MAS Financial Institutions Directory and the SGX register of Approved Traders.
As a replacement for the exchange's or the Clearing Member's gate. Every SGX order is checked against pre-execution limits at the Clearing Member's system or by SGX's own Pre-Trade Risk Controls module, and the matching engine applies the circuit breaker itself. This engine predicts those outcomes so the algorithm can avoid them; it does not substitute for them.
For entity-level obligations that do not attach to a single order. Business continuity, technology risk management, the register of Sponsored Access customers, trade surveillance and audit-trail retention are periodic or systemic obligations, not per-order checks. See singapore-mas-notice-on-cyber-hygiene-for-trading-systems for the MAS cyber baseline.
For board-lot and tick-size validation. Lot rounding and minimum bid size conformance are separate rejection paths — see minimum-fill-size-and-lot-rounding-logic.
Outside Singapore. The Forced Order Range, the Force Key and SGX's circuit breaker construction are SGX mechanisms. Do not carry the 10% band or the ±30 bids into another venue's gate.

Prerequisites

Firm control config (SingaporeAlgoControlConfig: algo_id, approved_trader_id, is_approved_trader_registered, has_cms_licence_or_exemption, is_pre_deployment_tested, has_kill_switch, max_order_value, limit_currency, max_order_rate_per_sec, circuit_breaker_band_pct, forced_order_range_bids).
Order payload (SgxOrderRequest: algo_id, symbol, side, quantity, limit_price, currency, min_bid_size, forced_order_range_ref_price, circuit_breaker_ref_price, opposite_best_price, is_circuit_breaker_eligible, session, force_key_confirmed, current_order_rate_per_sec).
The circuit breaker reference price: the last traded price at least five minutes earlier. Not the current mid, not the current last done.
Today's circuit breaker eligibility for the instrument. SGX-ST assesses this daily: the reference price at the start of the Market Day must be at least 0.50 in the instrument's underlying currency (JPY 500 for yen-denominated instruments).
The firm's own calibrated value and message-rate ceilings. SGX publishes neither — see references/standards.md.
For SGX-DT, the contract's own price limit, which replaces the 10% securities default.

Workflow

Reject structurally invalid input before auditing anything. A NaN or infinite price compares False against every ceiling and would otherwise be approved; a non-positive quantity yields a non-positive order value that passes every ceiling. Both raise ValueError, as does an order priced in a currency other than the ceiling's — comparing a USD notional against an SGD limit understates risk rather than overstating it.
Entity and Approved Trader governance. Audit the CMS licence or exemption, the current Approved Trader registration, and that the order's algo_id matches the config's. An order tagged for one algorithm audited against another's limits is a governance failure, not a formality $\implies$ REJECTED_UNLICENSED_ENTITY, REJECTED_UNREGISTERED_APPROVED_TRADER, REJECTED_ALGO_ID_MISMATCH.
Automated trading controls. Pre-deployment testing sign-off and an armed kill switch $\implies$ REJECTED_ALGO_NOT_TESTED, REJECTED_NO_KILL_SWITCH.
Pre-execution value limit. Value a limit order at its limit and a market order at the opposite best price. An order that can be priced by neither fails closed $\implies$ REJECTED_UNPRICEABLE_ORDER; over the firm's ceiling $\implies$ REJECTED_PRE_EXECUTION_LIMIT.
Circuit breaker band — check the potential trade price, not the order price. The mechanism runs only during continuous trading and only for eligible instruments. Then:
- Establish marketability: a market order always matches; a limit order matches only if it crosses opposite_best_price. Unknown book state resolves conservatively to "may be marketable", so a missing field can never make a breaching order look safe.
- Test the worst knowable potential trade price — the limit price for a limit order, the opposite best price for a market order — against $\pm$circuit_breaker_band_pct of the reference price. The band is inclusive, so a breach requires the price to be strictly outside it; compare unrounded and round only for reporting.
- A marketable order outside the band $\implies$ REJECTED_CIRCUIT_BREAKER_BAND. A non-marketable order outside the band is not rejected — it rests, and is recorded as a warning because it is a latent Cooling-Off trigger for whoever aggresses it later.
Forced Order Range. Compute the distance from the range's reference price in minimum bid sizes. Outside the range without a Force Key confirmation $\implies$ REJECTED_FORCED_ORDER_RANGE; with one, the order proceeds and the deliberate override is recorded as a warning.
Message rate ceiling. The caller owns the counter; this engine is stateless and cannot enforce a rate on its own $\implies$ REJECTED_ORDER_RATE_LIMIT.
Audit report generation. Every check runs; nothing short-circuits. Output SgxPreTradeComplianceReport carrying the full breaches tuple, the warnings tuple, and a status set to the most serious breach. Checks that did not run report None, never 0.0.

Full procedure: see references/workflows.md. Standards reference: see references/standards.md. Printable pre-flight checklist: see assets/checklist.md.

Common Pitfalls

Demanding a MAS algorithm registration number. MAS issues none. A gate that rejects SGX orders for a missing "MAS Algorithm Identifier" blocks entirely legitimate flow on a fabricated requirement, and — worse — creates false confidence that a real control is in place. What Singapore actually registers is the entity's licence and the Approved Trader's registration.
Treating the circuit breaker as an order-price collar. It is not. The Cooling-Off Period triggers when an incoming order seeks to match outside the band; the unfilled quantity is then rejected. A resting buy limit 40% below the market is not rejected on entry. A gate that blocks it produces false rejections; a gate that ignores the marketable case produces false approvals.
Comparing against the current mid or the current last done. The reference price is the last traded price at least five minutes earlier. In exactly the fast market where the mechanism matters, a live-mid comparison and the exchange will disagree — and the exchange wins.
Rounding the deviation before comparing it to the band. Rounding 10.0049% to 10.00% and then testing > 10.0 approves an order that is genuinely outside the band. Compare unrounded; round only for the report. The same applies to the value ceiling.
Letting NaN through a risk gate. float('nan') > limit is False, so every ceiling silently passes and the order is approved. Validate for finiteness before comparing, never after.
Applying the 10% band to SGX-DT. 10% is the SGX-ST securities figure. Derivatives price limits are set per contract under FTR 4.1.15 and the contract specifications. Hard-coding 10% across both is wrong in both directions.
Applying the band to every security and every session. Circuit breaker eligibility is assessed daily and requires a start-of-day reference price of at least 0.50 in the underlying currency. The mechanism does not run during the opening and closing routines.
Presenting a house limit as a regulatory threshold. SGX requires that pre-execution limits exist and be set by the Clearing Member; it publishes no figure. Shipping max_order_value=1_000_000.0 as a "MAS limit" is regulatory misinformation, and shipping it unreviewed means nobody ever calibrates it.
Treating the Force Key as a prohibition. Practice Note 8.6 permits an order outside the Forced Order Range once it has been confirmed. Blocking it outright breaks legitimate workflows; passing it silently loses the audit record of a deliberate override.
Reporting a figure for a check that never ran. A report that says "0.00% deviation" when no reference price was supplied asserts something the engine never evaluated. An audit trail that lies is worse than one that says "not evaluated".
Stopping at the first breach. An order can be unlicensed and over the value ceiling and outside the band at once. Remediation needs the full list, not the first item.

Verification

Instantiate MasSingaporeAlgoComplianceEngine. Audit a compliant marketable BUY (symbol="D05", quantity=1_000, limit_price=30.00, circuit_breaker_ref_price=30.00, opposite_best_price=30.00, min_bid_size=0.01, forced_order_range_ref_price=30.00, session="CONTINUOUS") against a fully compliant config $\implies$ verify SGX_PRE_TRADE_APPROVED, breaches == (), order_value == 30_000.0.
Confirm the circuit breaker bites on marketability, not on price alone: limit_price=36.00 with opposite_best_price=35.00 $\implies$ REJECTED_CIRCUIT_BREAKER_BAND; the same 36.00 order with opposite_best_price=None must still reject (conservative), while limit_price=20.00 with opposite_best_price=30.00 must return SGX_PRE_TRADE_APPROVED with a latent-trigger warning.
Confirm the band is inclusive and unrounded: limit_price=33.00 against a 30.00 reference (exactly +10%) must pass; limit_price=11.00049 against a 10.00 reference (+10.0049%) must reject.
Confirm scope gating: is_circuit_breaker_eligible=False, or session="CLOSING_ROUTINE", must leave circuit_breaker_deviation_pct at None with no band breach.
Confirm the Forced Order Range: 31.00 against a 30.00 reference at a 0.01 bid is 100 bids away $\implies$ REJECTED_FORCED_ORDER_RANGE; the same order with force_key_confirmed=True $\implies$ approved with a Force Key warning.
Confirm the gate fails closed on bad input: a NaN or infinite limit_price, a zero or negative quantity, an unknown side, and a currency that differs from limit_currency must each raise, never return an approved report.
Confirm the audit trail is complete: an unlicensed, unregistered, kill-switchless order that is also over the value ceiling, outside the band, outside the Forced Order Range and over the rate ceiling must carry all seven breaches, with status == "REJECTED_UNLICENSED_ENTITY".
Run the test suite:

python -m unittest discover -s skills/mas-singapore-algo-trading-guidelines/scripts

MAS Singapore Algo Trading Guidelines

When to Use

When NOT to Use

Prerequisites

Workflow

Common Pitfalls

Verification

Hands off to 6

Handed off from 7

When to Use

When NOT to Use

Prerequisites

Workflow

Common Pitfalls

Verification

Related Skills

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Handed off from 7