diff --git a/pkg/cmd/orders.go b/pkg/cmd/orders.go
index 1dd5d8c9d..6d7ae236a 100644
--- a/pkg/cmd/orders.go
+++ b/pkg/cmd/orders.go
@@ -256,7 +256,7 @@ var executeOrderCmd = &cobra.Command{
 		executionCtx, cancelExecution := context.WithCancel(ctx)
 		defer cancelExecution()
 
-		execution := &twap.Execution{
+		execution := &twap.StreamExecutor{
 			Session:        session,
 			Symbol:         symbol,
 			Side:           side,
diff --git a/pkg/twap/stream_executor.go b/pkg/twap/stream_executor.go
index 6ac4a809b..6d0e32b70 100644
--- a/pkg/twap/stream_executor.go
+++ b/pkg/twap/stream_executor.go
@@ -16,7 +16,8 @@ import (
 	"github.com/c9s/bbgo/pkg/types"
 )
 
-type Execution struct {
+// StreamExecutor is a TWAP execution that places orders on the best price by connecting to the real time market data stream.
+type StreamExecutor struct {
 	Session        *bbgo.ExchangeSession
 	Symbol         string
 	Side           types.SideType
@@ -52,21 +53,21 @@ type Execution struct {
 	mu sync.Mutex
 }
 
-func (e *Execution) connectMarketData(ctx context.Context) {
+func (e *StreamExecutor) connectMarketData(ctx context.Context) {
 	logrus.Infof("connecting market data stream...")
 	if err := e.marketDataStream.Connect(ctx); err != nil {
 		logrus.WithError(err).Errorf("market data stream connect error")
 	}
 }
 
-func (e *Execution) connectUserData(ctx context.Context) {
+func (e *StreamExecutor) connectUserData(ctx context.Context) {
 	logrus.Infof("connecting user data stream...")
 	if err := e.userDataStream.Connect(ctx); err != nil {
 		logrus.WithError(err).Errorf("user data stream connect error")
 	}
 }
 
-func (e *Execution) newBestPriceOrder() (orderForm types.SubmitOrder, err error) {
+func (e *StreamExecutor) newBestPriceOrder() (orderForm types.SubmitOrder, err error) {
 	book := e.orderBook.Copy()
 	sideBook := book.SideBook(e.Side)
 
@@ -201,7 +202,7 @@ func (e *Execution) newBestPriceOrder() (orderForm types.SubmitOrder, err error)
 	return orderForm, err
 }
 
-func (e *Execution) updateOrder(ctx context.Context) error {
+func (e *StreamExecutor) updateOrder(ctx context.Context) error {
 	book := e.orderBook.Copy()
 	sideBook := book.SideBook(e.Side)
 
@@ -284,13 +285,13 @@ func (e *Execution) updateOrder(ctx context.Context) error {
 	return nil
 }
 
-func (e *Execution) cancelActiveOrders() {
+func (e *StreamExecutor) cancelActiveOrders() {
 	gracefulCtx, gracefulCancel := context.WithTimeout(context.TODO(), 30*time.Second)
 	defer gracefulCancel()
 	e.activeMakerOrders.GracefulCancel(gracefulCtx, e.Session.Exchange)
 }
 
-func (e *Execution) orderUpdater(ctx context.Context) {
+func (e *StreamExecutor) orderUpdater(ctx context.Context) {
 	updateLimiter := rate.NewLimiter(rate.Every(3*time.Second), 1)
 	ticker := time.NewTimer(e.UpdateInterval)
 	defer ticker.Stop()
@@ -340,7 +341,7 @@ func (e *Execution) orderUpdater(ctx context.Context) {
 	}
 }
 
-func (e *Execution) cancelContextIfTargetQuantityFilled() bool {
+func (e *StreamExecutor) cancelContextIfTargetQuantityFilled() bool {
 	base := e.position.GetBase()
 
 	if base.Abs().Compare(e.TargetQuantity) >= 0 {
@@ -351,7 +352,7 @@ func (e *Execution) cancelContextIfTargetQuantityFilled() bool {
 	return false
 }
 
-func (e *Execution) handleTradeUpdate(trade types.Trade) {
+func (e *StreamExecutor) handleTradeUpdate(trade types.Trade) {
 	// ignore trades that are not in the symbol we interested
 	if trade.Symbol != e.Symbol {
 		return
@@ -367,7 +368,7 @@ func (e *Execution) handleTradeUpdate(trade types.Trade) {
 	logrus.Infof("position updated: %+v", e.position)
 }
 
-func (e *Execution) handleFilledOrder(order types.Order) {
+func (e *StreamExecutor) handleFilledOrder(order types.Order) {
 	logrus.Info(order.String())
 
 	// filled event triggers the order removal from the active order store
@@ -375,7 +376,7 @@ func (e *Execution) handleFilledOrder(order types.Order) {
 	e.cancelContextIfTargetQuantityFilled()
 }
 
-func (e *Execution) Run(parentCtx context.Context) error {
+func (e *StreamExecutor) Run(parentCtx context.Context) error {
 	e.mu.Lock()
 	e.stoppedC = make(chan struct{})
 	e.executionCtx, e.cancelExecution = context.WithCancel(parentCtx)
@@ -419,7 +420,7 @@ func (e *Execution) Run(parentCtx context.Context) error {
 	return nil
 }
 
-func (e *Execution) emitDone() {
+func (e *StreamExecutor) emitDone() {
 	e.mu.Lock()
 	if e.stoppedC == nil {
 		e.stoppedC = make(chan struct{})
@@ -428,7 +429,7 @@ func (e *Execution) emitDone() {
 	e.mu.Unlock()
 }
 
-func (e *Execution) Done() (c <-chan struct{}) {
+func (e *StreamExecutor) Done() (c <-chan struct{}) {
 	e.mu.Lock()
 	// if the channel is not allocated, it means it's not started yet, we need to return a closed channel
 	if e.stoppedC == nil {
@@ -448,7 +449,7 @@ func (e *Execution) Done() (c <-chan struct{}) {
 // We need to:
 // 1. stop the order updater (by using the execution context)
 // 2. the order updater cancels all open orders and close the user data stream
-func (e *Execution) Shutdown(shutdownCtx context.Context) {
+func (e *StreamExecutor) Shutdown(shutdownCtx context.Context) {
 	e.mu.Lock()
 	if e.cancelExecution != nil {
 		e.cancelExecution()