diff --git a/pkg/bbgo/scale.go b/pkg/bbgo/scale.go
index e4d36133d..da5a5bc52 100644
--- a/pkg/bbgo/scale.go
+++ b/pkg/bbgo/scale.go
@@ -151,7 +151,7 @@ func (s *LinearScale) Call(x float64) (y float64) {
 	if x <= s.Domain[0] {
 		return s.Range[0]
 	} else if x >= s.Domain[1] {
-		return s.Range[0]
+		return s.Range[1]
 	}
 
 	y = s.Range[0] + (x-s.Domain[0])*s.a
diff --git a/pkg/bbgo/scale_test.go b/pkg/bbgo/scale_test.go
index 3b46c2c7a..1ad86a0c4 100644
--- a/pkg/bbgo/scale_test.go
+++ b/pkg/bbgo/scale_test.go
@@ -75,6 +75,7 @@ func TestLinearScale(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Equal(t, "f(x) = 3.000000 + (x - 1000.000000) * 0.007000", scale.String())
 	assert.InDelta(t, 3, scale.Call(1000), delta)
+	assert.InDelta(t, 6.5, scale.Call(1500), delta)
 	assert.InDelta(t, 10, scale.Call(2000), delta)
 	for x := 1000; x <= 2000; x += 100 {
 		y := scale.Call(float64(x))
@@ -92,6 +93,7 @@ func TestLinearScale2(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Equal(t, "f(x) = 0.100000 + (x - 1.000000) * 0.150000", scale.String())
 	assert.InDelta(t, 0.1, scale.Call(1), delta)
+	assert.InDelta(t, 0.25, scale.Call(2), delta)
 	assert.InDelta(t, 0.4, scale.Call(3), delta)
 }
 
@@ -105,6 +107,7 @@ func TestLinearScaleNegative(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Equal(t, "f(x) = 0.100000 + (x - -1.000000) * 0.075000", scale.String())
 	assert.InDelta(t, 0.1, scale.Call(-1), delta)
+	assert.InDelta(t, 0.25, scale.Call(1), delta)
 	assert.InDelta(t, 0.4, scale.Call(3), delta)
 }