LX RISK MANAGEMENT ARCHITECTURE

    ┌─────────────────────────────────────────────────────────────────────────────┐
    │                              ORDER FLOW                                      │
    └─────────────────────────────────────────────────────────────────────────────┘
                                       │
                                       v
    ┌─────────────────────────────────────────────────────────────────────────────┐
    │                         PRE-TRADE RISK CHECKS                               │
    │  ┌─────────────────┐  ┌─────────────────┐  ┌─────────────────────────────┐  │
    │  │ Order Validation│  │  Balance Check  │  │    Position Limits Check    │  │
    │  │  Price/Size     │  │  Margin Calc    │  │   Exposure/Concentration    │  │
    │  └─────────────────┘  └─────────────────┘  └─────────────────────────────┘  │
    └─────────────────────────────────────────────────────────────────────────────┘
                                       │
                                       v
    ┌─────────────────────────────────────────────────────────────────────────────┐
    │                          MATCHING ENGINE                                     │
    └─────────────────────────────────────────────────────────────────────────────┘
                                       │
                                       v
    ┌─────────────────────────────────────────────────────────────────────────────┐
    │                       POST-TRADE RISK MONITORING                            │
    │  ┌─────────────────┐  ┌─────────────────┐  ┌─────────────────────────────┐  │
    │  │  Margin Health  │  │ Position Update │  │    Exposure Recalculation   │  │
    │  │  Monitoring     │  │   & P&L Calc    │  │       & Alerting            │  │
    │  └─────────────────┘  └─────────────────┘  └─────────────────────────────┘  │
    └─────────────────────────────────────────────────────────────────────────────┘
                                       │
                                       v
    ┌─────────────────────────────────────────────────────────────────────────────┐
    │                       AUTOMATED RISK RESPONSES                              │
    │  ┌─────────────────┐  ┌─────────────────┐  ┌─────────────────────────────┐  │
    │  │   Liquidation   │  │ Circuit Breaker │  │      Kill Switch            │  │
    │  │     Engine      │  │    Trigger      │  │    (Emergency Halt)         │  │
    │  └─────────────────┘  └─────────────────┘  └─────────────────────────────┘  │
    └─────────────────────────────────────────────────────────────────────────────┘
                                       │
                                       v
    ┌─────────────────────────────────────────────────────────────────────────────┐
    │                         INSURANCE FUND / ADL                                │
    │  ┌─────────────────────────────────────────────────────────────────────┐    │
    │  │  Insurance Fund covers bankrupt positions; ADL for extreme events   │    │
    │  └─────────────────────────────────────────────────────────────────────┘    │
    └─────────────────────────────────────────────────────────────────────────────┘

interface GlobalRiskConfig {
  // Circuit breaker thresholds
  circuitBreaker: {
    priceMovementThreshold: 0.10,      // 10% price move triggers halt
    volumeSpikeThreshold: 10,           // 10x normal volume
    haltDurationSeconds: 300,           // 5-minute cooling period
  },

  // Position limits
  positionLimits: {
    maxLeverageSpot: 10,                // 10x max for margin
    maxLeveragePerp: 50,                // 50x max for perpetuals
    maxPositionUSD: 10_000_000,         // $10M max position
    maxConcentration: 0.25,             // 25% max in single asset
  },

  // Margin requirements
  margin: {
    initialMarginSpot: 0.10,            // 10% initial (10x leverage)
    maintenanceMarginSpot: 0.05,        // 5% maintenance
    initialMarginPerp: 0.02,            // 2% initial (50x leverage)
    maintenanceMarginPerp: 0.005,       // 0.5% maintenance
  },

  // Liquidation
  liquidation: {
    liquidationFee: 0.005,              // 0.5% liquidation fee
    insuranceFundContribution: 0.20,    // 20% to insurance fund
    adlThreshold: 0.80,                 // ADL at 80% insurance depletion
  },
}

func (r *RiskEngine) ValidateOrder(order *Order) error {
    // 1. Structural validation
    if err := r.validateOrderStructure(order); err != nil {
        return fmt.Errorf("invalid order structure: %w", err)
    }

    // 2. Price band check
    if err := r.checkPriceBands(order); err != nil {
        return fmt.Errorf("price band violation: %w", err)
    }

    // 3. Balance/margin check
    if err := r.checkMarginRequirement(order); err != nil {
        return fmt.Errorf("insufficient margin: %w", err)
    }

    // 4. Position limit check
    if err := r.checkPositionLimits(order); err != nil {
        return fmt.Errorf("position limit exceeded: %w", err)
    }

    // 5. Rate limit check
    if err := r.checkRateLimits(order.UserID); err != nil {
        return fmt.Errorf("rate limit exceeded: %w", err)
    }

    return nil
}

type RiskMetrics struct {
    // Account-level metrics
    AccountEquity        float64   `json:"account_equity"`
    UnrealizedPnL        float64   `json:"unrealized_pnl"`
    MarginUsed           float64   `json:"margin_used"`
    MarginAvailable      float64   `json:"margin_available"`
    MarginLevel          float64   `json:"margin_level"`      // equity/margin
    HealthFactor         float64   `json:"health_factor"`     // >1 = healthy

    // Position-level metrics
    TotalExposure        float64   `json:"total_exposure"`
    LargestPosition      float64   `json:"largest_position"`
    Concentration        float64   `json:"concentration"`     // % in single asset

    // Market-level metrics
    TotalOpenInterest    float64   `json:"total_open_interest"`
    FundingRate          float64   `json:"funding_rate"`
    MarkPrice            float64   `json:"mark_price"`
    IndexPrice           float64   `json:"index_price"`
}

GET /api/v1/risk/status
Authorization: Bearer {api_key}

{
  "account_id": "acc_123456",
  "equity": 100000.00,
  "margin_used": 25000.00,
  "margin_available": 75000.00,
  "health_factor": 4.0,
  "risk_level": "low",
  "positions": 3,
  "total_exposure_usd": 250000.00,
  "largest_position_pct": 0.40,
  "warnings": [],
  "timestamp": "2024-01-15T10:30:00Z"
}

GET /api/v1/risk/positions
Authorization: Bearer {api_key}

{
  "positions": [
    {
      "symbol": "BTC-PERP",
      "side": "long",
      "size": 2.5,
      "entry_price": 42000.00,
      "mark_price": 43500.00,
      "liquidation_price": 38640.00,
      "margin_used": 10500.00,
      "unrealized_pnl": 3750.00,
      "leverage": 10.0,
      "margin_ratio": 0.097
    }
  ]
}

GET /api/v1/risk/config
Authorization: Bearer {api_key}

PUT /api/v1/risk/config
Authorization: Bearer {api_key}
Content-Type: application/json

{
  "max_leverage": 25,
  "position_limit_usd": 500000,
  "risk_alerts": {
    "margin_warning_threshold": 0.80,
    "liquidation_warning_threshold": 0.90
  }
}

// Subscribe to risk alerts
ws.send(JSON.stringify({
  op: 'subscribe',
  channel: 'risk',
  params: { account_id: 'acc_123456' }
}))

// Receive alerts
{
  "channel": "risk",
  "type": "margin_warning",
  "data": {
    "account_id": "acc_123456",
    "current_margin_level": 0.15,
    "warning_threshold": 0.20,
    "action_required": "reduce_positions_or_add_margin",
    "time_to_liquidation_estimate": "2h 15m",
    "timestamp": "2024-01-15T10:30:00Z"
  }
}