Risk Controls

Pre-trade risk engine (port 5032)

The OMS calls POST /check on the risk-engine synchronously before routing every order. If any check fails, the order is rejected with a specific reason code. If the risk-engine is unreachable (3s timeout), the order is rejected — real firms sooner halt trading than bypass pre-trade risk.

Checks

#	Check	Code	Default	What it prevents
1	Fat-finger price collar	FAT_FINGER_PRICE	5% from mid	Typo prices
2	Duplicate order detection	DUPLICATE_ORDER	500ms window	Double-clicks
3	Max open orders per user	MAX_OPEN_ORDERS	50 orders	Runaway algos
4	Self-cross prevention	SELF_CROSS	—	Own BUY crossing own SELL
5	Order size vs ADV	ORDER_SIZE_VS_ADV	10% of ADV	Market impact
6	Rate limiting	RATE_LIMIT	10 orders/sec	Algo floods

Configuration

All thresholds are runtime-editable via PUT /config with no restart:

{
  "fatFingerPct": 5.0,
  "maxOpenOrders": 50,
  "duplicateWindowMs": 500,
  "maxOrdersPerSecond": 10,
  "maxAdvPct": 10.0
}

Live positions

The risk-engine tracks positions from orders.filled bus events in real-time.

• GET /positions/:userId — per-symbol: net qty, avg price, mark price, unrealised/realised/total P&L
• GET /positions — all users’ positions

P&L calculation

• Unrealised: netQty * (markPrice - avgPrice) — updated on every price refresh (5s)
• Realised: accumulated when fills reduce or flip a position
• Total: unrealised + realised

Panels

• Risk Dashboard (risk-manager, desk-head, admin, compliance): firm-wide view with per-user rolled-up P&L
• My Positions (all traders): authenticated user’s own positions with total row