Add two risk controls for strategies: postion and circuit break.

doc/topics/riskcontrols.md

@@ -0,0 +1,87 @@
+# Risk Control
+------------
+
+### 1. Introduction
+
+Two types of risk controls for strategies is created:
+- Position-limit Risk Control (pkg/risk/riskcontrol/position.go)
+- Circuit-break Risk Control (pkg/risk/riskcontrol/circuit_break.go)
+
+### 2. Position-Limit Risk Control
+
+Initialization:
+```
+    s.positionRiskControl = riskcontrol.NewPositionRiskControl(s.HardLimit, s.Quantity, s.orderExecutor.TradeCollector())
+    s.positionRiskControl.OnReleasePosition(func(quantity fixedpoint.Value, side types.SideType) {
+        createdOrders, err := s.orderExecutor.SubmitOrders(ctx, types.SubmitOrder{
+            Symbol:   s.Symbol,
+            Market:   s.Market,
+            Side:     side,
+            Type:     types.OrderTypeMarket,
+            Quantity: quantity,
+        })
+        if err != nil {
+            log.WithError(err).Errorf("failed to submit orders")
+            return
+        }
+        log.Infof("created orders: %+v", createdOrders)
+    })
+```
+
+Strategy should provide OnReleasePosition callback, which will be called when position (positive or negative) is over hard limit.
+
+Modify quantity before submitting orders:
+
+```
+    buyQuantity, sellQuantity := s.positionRiskControl.ModifiedQuantity(s.Position.Base)
+```
+
+It calculates buy and sell quantity shrinking by hard limit and position.
+
+### 3. Circuit-Break Risk Control
+
+Initialization
+```
+    s.circuitBreakRiskControl = riskcontrol.NewCircuitBreakRiskControl(
+        s.Position,
+        session.StandardIndicatorSet(s.Symbol).EWMA(
+            types.IntervalWindow{
+                Window:   EWMAWindow,
+                Interval: types.Interval1m,
+            }),
+        s.CircuitBreakCondition,
+        s.ProfitStats)
+```
+Should pass in position and profit states. Also need an price EWMA to calculate unrealized profit.
+
+
+Validate parameters:
+```
+    if s.CircuitBreakCondition.Float64() > 0 {
+        return fmt.Errorf("circuitBreakCondition should be non-positive")
+    }
+    return nil
+```
+Circuit break condition should be non-greater than zero.
+
+Check for circuit break before submitting orders:
+```
+    // Circuit break when accumulated losses are over break condition
+    if s.circuitBreakRiskControl.IsHalted() {
+        return
+    }
+
+    submitOrders, err := s.generateSubmitOrders(ctx)
+    if err != nil {
+        log.WithError(err).Error("failed to generate submit orders")
+        return
+    }
+    log.Infof("submit orders: %+v", submitOrders)
+
+    if s.DryRun {
+        log.Infof("dry run, not submitting orders")
+        return
+    }
+```
+
+Notice that if there are multiple place to submit orders, it is recommended to check in one place in Strategy.Run() and re-use that flag before submitting orders. That can avoid duplicated logs generated from IsHalted().

pkg/risk/riskcontrol/circuit_break.go

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+package riskcontrol
+
+import (
+	"github.com/c9s/bbgo/pkg/fixedpoint"
+	"github.com/c9s/bbgo/pkg/indicator"
+	"github.com/c9s/bbgo/pkg/types"
+	log "github.com/sirupsen/logrus"
+)
+
+type CircuitBreakRiskControl struct {
+	// Since price could be fluctuated large,
+	// use an EWMA to smooth it in running time
+	price          *indicator.EWMA
+	position       *types.Position
+	profitStats    *types.ProfitStats
+	breakCondition fixedpoint.Value
+}
+
+func NewCircuitBreakRiskControl(
+	position *types.Position,
+	price *indicator.EWMA,
+	breakCondition fixedpoint.Value,
+	profitStats *types.ProfitStats) *CircuitBreakRiskControl {
+
+	return &CircuitBreakRiskControl{
+		price:          price,
+		position:       position,
+		profitStats:    profitStats,
+		breakCondition: breakCondition,
+	}
+}
+
+// IsHalted returns whether we reached the circuit break condition set for this day?
+func (c *CircuitBreakRiskControl) IsHalted() bool {
+	var unrealized = c.position.UnrealizedProfit(fixedpoint.NewFromFloat(c.price.Last(0)))
+	log.Infof("[CircuitBreakRiskControl] Realized P&L = %v, Unrealized P&L = %v\n",
+		c.profitStats.TodayPnL,
+		unrealized)
+	return unrealized.Add(c.profitStats.TodayPnL).Compare(c.breakCondition) <= 0
+}

pkg/risk/riskcontrol/circuit_break_test.go

@@ -0,0 +1,79 @@
+package riskcontrol
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/c9s/bbgo/pkg/fixedpoint"
+	"github.com/c9s/bbgo/pkg/indicator"
+	"github.com/c9s/bbgo/pkg/types"
+)
+
+func Test_IsHalted(t *testing.T) {
+
+	var (
+		price          = 30000.00
+		realizedPnL    = fixedpoint.NewFromFloat(-100.0)
+		breakCondition = fixedpoint.NewFromFloat(-500.00)
+	)
+
+	window := types.IntervalWindow{Window: 30, Interval: types.Interval1m}
+	priceEWMA := &indicator.EWMA{IntervalWindow: window}
+	priceEWMA.Update(price)
+
+	cases := []struct {
+		name        string
+		position    fixedpoint.Value
+		averageCost fixedpoint.Value
+		isHalted    bool
+	}{
+		{
+			name:        "PositivePositionReachBreakCondition",
+			position:    fixedpoint.NewFromFloat(10.0),
+			averageCost: fixedpoint.NewFromFloat(30040.0),
+			isHalted:    true,
+		}, {
+			name:        "PositivePositionOverBreakCondition",
+			position:    fixedpoint.NewFromFloat(10.0),
+			averageCost: fixedpoint.NewFromFloat(30050.0),
+			isHalted:    true,
+		}, {
+			name:        "PositivePositionUnderBreakCondition",
+			position:    fixedpoint.NewFromFloat(10.0),
+			averageCost: fixedpoint.NewFromFloat(30030.0),
+			isHalted:    false,
+		}, {
+			name:        "NegativePositionReachBreakCondition",
+			position:    fixedpoint.NewFromFloat(-10.0),
+			averageCost: fixedpoint.NewFromFloat(29960.0),
+			isHalted:    true,
+		}, {
+			name:        "NegativePositionOverBreakCondition",
+			position:    fixedpoint.NewFromFloat(-10.0),
+			averageCost: fixedpoint.NewFromFloat(29950.0),
+			isHalted:    true,
+		}, {
+			name:        "NegativePositionUnderBreakCondition",
+			position:    fixedpoint.NewFromFloat(-10.0),
+			averageCost: fixedpoint.NewFromFloat(29970.0),
+			isHalted:    false,
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			var riskControl = NewCircuitBreakRiskControl(
+				&types.Position{
+					Base:        tc.position,
+					AverageCost: tc.averageCost,
+				},
+				priceEWMA,
+				breakCondition,
+				&types.ProfitStats{
+					TodayPnL: realizedPnL,
+				},
+			)
+			assert.Equal(t, tc.isHalted, riskControl.IsHalted())
+		})
+	}
+}

pkg/risk/riskcontrol/position.go

@@ -0,0 +1,42 @@
+package riskcontrol
+
+import (
+	"github.com/c9s/bbgo/pkg/bbgo"
+	"github.com/c9s/bbgo/pkg/fixedpoint"
+	"github.com/c9s/bbgo/pkg/types"
+	log "github.com/sirupsen/logrus"
+)
+
+//go:generate callbackgen -type PositionRiskControl
+type PositionRiskControl struct {
+	hardLimit fixedpoint.Value
+	quantity  fixedpoint.Value
+
+	releasePositionCallbacks []func(quantity fixedpoint.Value, side types.SideType)
+}
+
+func NewPositionRiskControl(hardLimit, quantity fixedpoint.Value, tradeCollector *bbgo.TradeCollector) *PositionRiskControl {
+	p := &PositionRiskControl{
+		hardLimit: hardLimit,
+		quantity:  quantity,
+	}
+	// register position update handler: check if position is over hardlimit
+	tradeCollector.OnPositionUpdate(func(position *types.Position) {
+		if fixedpoint.Compare(position.Base, hardLimit) > 0 {
+			log.Infof("Position %v is over hardlimit %v, releasing:\n", position.Base, hardLimit)
+			p.EmitReleasePosition(position.Base.Sub(hardLimit), types.SideTypeSell)
+		} else if fixedpoint.Compare(position.Base, hardLimit.Neg()) < 0 {
+			log.Infof("Position %v is over hardlimit %v, releasing:\n", position.Base, hardLimit)
+			p.EmitReleasePosition(position.Base.Neg().Sub(hardLimit), types.SideTypeBuy)
+		}
+	})
+	return p
+}
+
+// ModifiedQuantity returns quantity controlled by position risks
+// For buy orders, mod quantity = min(hardlimit - position, quanity), limiting by positive position
+// For sell orders, mod quantity = min(hardlimit - (-position), quanity), limiting by negative position
+func (p *PositionRiskControl) ModifiedQuantity(position fixedpoint.Value) (buyQuanity, sellQuantity fixedpoint.Value) {
+	return fixedpoint.Min(p.hardLimit.Sub(position), p.quantity),
+		fixedpoint.Min(p.hardLimit.Add(position), p.quantity)
+}

pkg/risk/riskcontrol/position_test.go

@@ -0,0 +1,92 @@
+package riskcontrol
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/c9s/bbgo/pkg/bbgo"
+	"github.com/c9s/bbgo/pkg/fixedpoint"
+	"github.com/c9s/bbgo/pkg/types"
+)
+
+func Test_ModifiedQuantity(t *testing.T) {
+
+	riskControl := NewPositionRiskControl(fixedpoint.NewFromInt(10), fixedpoint.NewFromInt(2), &bbgo.TradeCollector{})
+
+	cases := []struct {
+		name         string
+		position     fixedpoint.Value
+		buyQuantity  fixedpoint.Value
+		sellQuantity fixedpoint.Value
+	}{
+		{
+			name:         "BuyOverHardLimit",
+			position:     fixedpoint.NewFromInt(9),
+			buyQuantity:  fixedpoint.NewFromInt(1),
+			sellQuantity: fixedpoint.NewFromInt(2),
+		},
+		{
+			name:         "SellOverHardLimit",
+			position:     fixedpoint.NewFromInt(-9),
+			buyQuantity:  fixedpoint.NewFromInt(2),
+			sellQuantity: fixedpoint.NewFromInt(1),
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			buyQuantity, sellQuantity := riskControl.ModifiedQuantity(tc.position)
+			assert.Equal(t, tc.buyQuantity, buyQuantity)
+			assert.Equal(t, tc.sellQuantity, sellQuantity)
+		})
+	}
+}
+
+func TestReleasePositionCallbacks(t *testing.T) {
+
+	var position fixedpoint.Value
+
+	tradeCollector := &bbgo.TradeCollector{}
+	riskControl := NewPositionRiskControl(fixedpoint.NewFromInt(10), fixedpoint.NewFromInt(2), tradeCollector)
+	riskControl.OnReleasePosition(func(quantity fixedpoint.Value, side types.SideType) {
+		if side == types.SideTypeBuy {
+			position = position.Add(quantity)
+		} else {
+			position = position.Sub(quantity)
+		}
+	})
+
+	cases := []struct {
+		name           string
+		position       fixedpoint.Value
+		resultPosition fixedpoint.Value
+	}{
+		{
+			name:           "PostivePositionWithinLimit",
+			position:       fixedpoint.NewFromInt(8),
+			resultPosition: fixedpoint.NewFromInt(8),
+		},
+		{
+			name:           "NegativePositionWithinLimit",
+			position:       fixedpoint.NewFromInt(-8),
+			resultPosition: fixedpoint.NewFromInt(-8),
+		},
+		{
+			name:           "PostivePositionOverLimit",
+			position:       fixedpoint.NewFromInt(11),
+			resultPosition: fixedpoint.NewFromInt(10),
+		},
+		{
+			name:           "NegativePositionOverLimit",
+			position:       fixedpoint.NewFromInt(-11),
+			resultPosition: fixedpoint.NewFromInt(-10),
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			position = tc.position
+			tradeCollector.EmitPositionUpdate(&types.Position{Base: tc.position})
+			assert.Equal(t, tc.resultPosition, position)
+		})
+	}
+}

pkg/risk/riskcontrol/positionriskcontrol_callbacks.go

@@ -0,0 +1,18 @@
+// Code generated by "callbackgen -type PositionRiskControl"; DO NOT EDIT.
+
+package riskcontrol
+
+import (
+	"github.com/c9s/bbgo/pkg/fixedpoint"
+	"github.com/c9s/bbgo/pkg/types"
+)
+
+func (p *PositionRiskControl) OnReleasePosition(cb func(quantity fixedpoint.Value, side types.SideType)) {
+	p.releasePositionCallbacks = append(p.releasePositionCallbacks, cb)
+}
+
+func (p *PositionRiskControl) EmitReleasePosition(quantity fixedpoint.Value, side types.SideType) {
+	for _, cb := range p.releasePositionCallbacks {
+		cb(quantity, side)
+	}
+}