diff --git a/pkg/indicator/boll.go b/pkg/indicator/boll.go
index 5301a97d1..0206a46c8 100644
--- a/pkg/indicator/boll.go
+++ b/pkg/indicator/boll.go
@@ -20,6 +20,8 @@ Bollinger Bands
 Bollinger Bands Technical indicator guide:
 - https://www.fidelity.com/learning-center/trading-investing/technical-analysis/technical-indicator-guide/bollinger-bands
 */
+
+//go:generate callbackgen -type BOLL
 type BOLL struct {
 	types.IntervalWindow
 
@@ -32,6 +34,16 @@ type BOLL struct {
 	DownBand Float64Slice
 
 	EndTime time.Time
+
+	updateCallbacks []func(sma, upBand, downBand float64)
+}
+
+func (inc *BOLL) LastUpBand() float64 {
+	return inc.UpBand[len(inc.UpBand)-1]
+}
+
+func (inc *BOLL) LastDownBand() float64 {
+	return inc.DownBand[len(inc.DownBand)-1]
 }
 
 func (inc *BOLL) LastSMA() float64 {