diff --git a/pkg/strategy/grid/strategy.go b/pkg/strategy/grid/strategy.go
index d19c5c7d4..a16efe08a 100644
--- a/pkg/strategy/grid/strategy.go
+++ b/pkg/strategy/grid/strategy.go
@@ -3,13 +3,13 @@ package grid
 import (
 	"context"
 	"fmt"
-	"hash/fnv"
 	"sync"
 
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 
 	"github.com/c9s/bbgo/pkg/bbgo"
+	"github.com/c9s/bbgo/pkg/exchange/max"
 	"github.com/c9s/bbgo/pkg/fixedpoint"
 	"github.com/c9s/bbgo/pkg/service"
 	"github.com/c9s/bbgo/pkg/types"
@@ -99,7 +99,7 @@ type Strategy struct {
 	activeOrders *bbgo.LocalActiveOrderBook
 
 	// groupID is the group ID used for the strategy instance for canceling orders
-	groupID int64
+	groupID uint32
 }
 
 func (s *Strategy) ID() string {
@@ -500,7 +500,7 @@ func (s *Strategy) Run(ctx context.Context, orderExecutor bbgo.OrderExecutor, se
 	}
 
 	instanceID := fmt.Sprintf("grid-%s-%d-%d-%d", s.Symbol, s.GridNum, s.UpperPrice, s.LowerPrice)
-	s.groupID = generateGroupID(instanceID)
+	s.groupID = max.GenerateGroupID(instanceID)
 	log.Infof("using group id %d from fnv(%s)", s.groupID, instanceID)
 
 	var stateLoaded = false
@@ -537,7 +537,6 @@ func (s *Strategy) Run(ctx context.Context, orderExecutor bbgo.OrderExecutor, se
 
 	s.Notify("current position %+v", s.state.Position)
 
-
 	s.orderStore = bbgo.NewOrderStore(s.Symbol)
 	s.orderStore.BindStream(session.Stream)
 
@@ -590,9 +589,3 @@ func (s *Strategy) Run(ctx context.Context, orderExecutor bbgo.OrderExecutor, se
 
 	return nil
 }
-
-func generateGroupID(s string) int64 {
-	h := fnv.New32a()
-	h.Write([]byte(s))
-	return int64(h.Sum32())
-}
diff --git a/pkg/strategy/xmaker/strategy.go b/pkg/strategy/xmaker/strategy.go
index 2b76122e2..799bc2e08 100644
--- a/pkg/strategy/xmaker/strategy.go
+++ b/pkg/strategy/xmaker/strategy.go
@@ -3,7 +3,6 @@ package xmaker
 import (
 	"context"
 	"fmt"
-	"hash/fnv"
 	"math"
 	"sync"
 	"time"
@@ -11,6 +10,7 @@ import (
 	"github.com/sirupsen/logrus"
 
 	"github.com/c9s/bbgo/pkg/bbgo"
+	"github.com/c9s/bbgo/pkg/exchange/max"
 	"github.com/c9s/bbgo/pkg/fixedpoint"
 	"github.com/c9s/bbgo/pkg/service"
 	"github.com/c9s/bbgo/pkg/types"
@@ -74,7 +74,7 @@ type Strategy struct {
 	orderStore *bbgo.OrderStore
 
 	lastPrice float64
-	groupID   int64
+	groupID   uint32
 
 	stopC chan struct{}
 }
@@ -398,7 +398,7 @@ func (s *Strategy) CrossRun(ctx context.Context, _ bbgo.OrderExecutionRouter, se
 
 	// restore state
 	instanceID := fmt.Sprintf("%s-%s", ID, s.Symbol)
-	s.groupID = generateGroupID(instanceID)
+	s.groupID = max.GenerateGroupID(instanceID)
 	log.Infof("using group id %d from fnv(%s)", s.groupID, instanceID)
 
 	var state State
@@ -482,8 +482,3 @@ func (s *Strategy) CrossRun(ctx context.Context, _ bbgo.OrderExecutionRouter, se
 	return nil
 }
 
-func generateGroupID(s string) int64 {
-	h := fnv.New32a()
-	h.Write([]byte(s))
-	return int64(h.Sum32())
-}
diff --git a/pkg/types/order.go b/pkg/types/order.go
index 927922494..9961eed10 100644
--- a/pkg/types/order.go
+++ b/pkg/types/order.go
@@ -108,7 +108,7 @@ type SubmitOrder struct {
 
 	TimeInForce string `json:"timeInForce,omitempty" db:"time_in_force"` // GTC, IOC, FOK
 
-	GroupID int64 `json:"groupID,omitempty"`
+	GroupID uint32 `json:"groupID,omitempty"`
 
 	MarginSideEffect MarginOrderSideEffectType `json:"marginSideEffect,omitempty"` // AUTO_REPAY = repay, MARGIN_BUY = borrow, defaults to  NO_SIDE_EFFECT
 }