diff --git a/indicators.go b/indicators.go
index 2ea0ab4..be316b0 100644
--- a/indicators.go
+++ b/indicators.go
@@ -1,6 +1,9 @@
 package autotrader
 
-import "math"
+import (
+	"math"
+	"time"
+)
 
 // RSI calculates the Relative Strength Index for a given Series. Typically, the input series is the Close column of a DataFrame. Returns a Series of RSI values of the same length as the input.
 //
@@ -22,6 +25,7 @@ func RSI(series *FloatSeries, periods int) *FloatSeries {
 	avgLoss := &FloatSeries{delta.Copy().
 		Map(func(i int, val float64) float64 { return math.Abs(math.Min(val, 0)) }).
 		Rolling(periods).Average()}
+
 	// Calculate the RSI.
 	return avgGain.Map(func(i int, val float64) float64 {
 		loss := avgLoss.Float(i)
@@ -29,7 +33,7 @@ func RSI(series *FloatSeries, periods int) *FloatSeries {
 			return float64(100)
 		}
 		return float64(100 - 100/(1+val/loss))
-	})
+	}).SetName("RSI")
 }
 
 // Ichimoku calculates the Ichimoku Cloud for a given Series. Returns a DataFrame of the same length as the input with float64 values. The series input must contain only float64 values, which are traditionally the close prices.
@@ -45,29 +49,40 @@ func RSI(series *FloatSeries, periods int) *FloatSeries {
 //   - LeadingA
 //   - LeadingB
 //   - Lagging
-func Ichimoku(series *FloatSeries, convPeriod, basePeriod, leadingPeriods int) *Frame {
+func Ichimoku(series *IndexedSeries[UnixTime], convPeriod, basePeriod, leadingPeriods int) *IndexedFrame[UnixTime] {
+	// TODO: make this run concurrently.
+
 	// Calculate the Conversion Line.
 	conv := series.Copy().Rolling(convPeriod).Max().Add(series.Copy().Rolling(convPeriod).Min()).
-		Map(func(i int, val any) any {
+		Map(func(_ UnixTime, _ int, val any) any {
 			return val.(float64) / float64(2)
 		})
 	// Calculate the Base Line.
 	base := series.Copy().Rolling(basePeriod).Max().Add(series.Copy().Rolling(basePeriod).Min()).
-		Map(func(i int, val any) any {
+		Map(func(_ UnixTime, _ int, val any) any {
 			return val.(float64) / float64(2)
 		})
+
 	// Calculate the Leading Span A.
 	leadingA := conv.Copy().Rolling(leadingPeriods).Max().Add(base.Copy().Rolling(leadingPeriods).Max()).
-		Map(func(i int, val any) any {
+		Map(func(_ UnixTime, _ int, val any) any {
 			return val.(float64) / float64(2)
 		})
 	// Calculate the Leading Span B.
 	leadingB := series.Copy().Rolling(leadingPeriods).Max().Add(series.Copy().Rolling(leadingPeriods).Min()).
-		Map(func(i int, val any) any {
+		Map(func(_ UnixTime, _ int, val any) any {
 			return val.(float64) / float64(2)
 		})
+
 	// Calculate the Lagging Span.
-	// lagging := series.Shift(-leadingPeriods)
+	lagging := series.Copy().ShiftIndex(-leadingPeriods, UnixTimeStep(time.Hour))
+
 	// Return a DataFrame of the results.
-	return NewFrame(conv, base, leadingA, leadingB)
+	return NewIndexedFrame(
+		conv.SetName("Conversion"),
+		base.SetName("Base"),
+		leadingA.SetName("LeadingA"),
+		leadingB.SetName("LeadingB"),
+		lagging.SetName("Lagging"),
+	)
 }
diff --git a/series.go b/series.go
index e3c29cf..3d68931 100644
--- a/series.go
+++ b/series.go
@@ -435,14 +435,14 @@ func NewRollingSeries(series *Series, period int) *RollingSeries {
 	return &RollingSeries{series, period}
 }
 
-// Period returns a slice of 'any' values with a length up to the period of the RollingSeries. The last item in the slice is the item at i. If i is out of bounds, nil is returned.
-func (s *RollingSeries) Period(i int) []any {
+// Period returns a slice of 'any' values with a length up to the period of the RollingSeries. The last item in the slice is the item at row. If row is out of bounds, nil is returned.
+func (s *RollingSeries) Period(row int) []any {
 	items := make([]any, 0, s.period)
-	i = EasyIndex(i, s.series.Len())
-	if i < 0 || i >= s.series.Len() {
+	row = EasyIndex(row, s.series.Len())
+	if row < 0 || row >= s.series.Len() {
 		return items
 	}
-	for j := i; j > i-s.period && j >= 0; j-- {
+	for j := row; j > row-s.period && j >= 0; j-- {
 		items = slices.Insert(items, 0, s.series.Value(j))
 	}
 	return items
diff --git a/series_indexed.go b/series_indexed.go
index 435b9ea..992a7b1 100644
--- a/series_indexed.go
+++ b/series_indexed.go
@@ -89,6 +89,18 @@ func (s *IndexedSeries[I]) Filter(f func(i int, val any) bool) *IndexedSeries[I]
 	return s
 }
 
+func (s *IndexedSeries[I]) Float(i int) float64 {
+	return s.series.Float(i)
+}
+
+func (s *IndexedSeries[I]) FloatIndex(index I) float64 {
+	row := s.Row(index)
+	if row < 0 {
+		return 0.0
+	}
+	return s.series.Float(row)
+}
+
 func (s *IndexedSeries[I]) ForEach(f func(i int, val any)) *IndexedSeries[I] {
 	_ = s.series.ForEach(f)
 	return s
@@ -240,6 +252,10 @@ func (s *IndexedSeries[I]) ReverseIndexes() *IndexedSeries[I] {
 	return s
 }
 
+func (s *IndexedSeries[I]) Rolling(period int) *IndexedRollingSeries[I] {
+	return NewIndexedRollingSeries(s, period)
+}
+
 func (s *IndexedSeries[I]) SetName(name string) *IndexedSeries[I] {
 	_ = s.series.SetName(name)
 	return s
@@ -314,3 +330,51 @@ func (s *IndexedSeries[I]) Values() []any {
 func (s *IndexedSeries[I]) ValueRange(start, count int) []any {
 	return s.series.ValueRange(start, count)
 }
+
+type IndexedRollingSeries[I comparable] struct {
+	rolling *RollingSeries
+	series  *IndexedSeries[I]
+}
+
+func NewIndexedRollingSeries[I comparable](series *IndexedSeries[I], period int) *IndexedRollingSeries[I] {
+	return &IndexedRollingSeries[I]{NewRollingSeries(series.series, period), series}
+}
+
+func (s *IndexedRollingSeries[I]) Period(row int) []any {
+	return s.rolling.Period(row)
+}
+
+func (s *IndexedRollingSeries[I]) Max() *IndexedSeries[I] {
+	_ = s.rolling.Max() // Mutate the underlying series.
+	return s.series
+}
+
+func (s *IndexedRollingSeries[I]) Min() *IndexedSeries[I] {
+	_ = s.rolling.Min() // Mutate the underlying series.
+	return s.series
+}
+
+func (s *IndexedRollingSeries[I]) Average() *IndexedSeries[I] {
+	_ = s.rolling.Average() // Mutate the underlying series.
+	return s.series
+}
+
+func (s *IndexedRollingSeries[I]) Mean() *IndexedSeries[I] {
+	_ = s.rolling.Mean() // Mutate the underlying series.
+	return s.series
+}
+
+func (s *IndexedRollingSeries[I]) Median() *IndexedSeries[I] {
+	_ = s.rolling.Median() // Mutate the underlying series.
+	return s.series
+}
+
+func (s *IndexedRollingSeries[I]) EMA() *IndexedSeries[I] {
+	_ = s.rolling.EMA() // Mutate the underlying series.
+	return s.series
+}
+
+func (s *IndexedRollingSeries[I]) StdDev() *IndexedSeries[I] {
+	_ = s.rolling.StdDev() // Mutate the underlying series.
+	return s.series
+}
diff --git a/utils.go b/utils.go
index 40294d0..eabeb41 100644
--- a/utils.go
+++ b/utils.go
@@ -14,10 +14,18 @@ const float64Tolerance = float64(1e-6)
 var ErrNotASignedNumber = errors.New("not a signed number")
 
 // Crossover returns true if the latest a value crosses above the latest b value, but only if it just happened. For example, if a series is [1, 2, 3, 4, 5] and b series is [1, 2, 3, 4, 3], then Crossover(a, b) returns false because the latest a value is 5 and the latest b value is 3. However, if a series is [1, 2, 3, 4, 5] and b series is [1, 2, 3, 4, 6], then Crossover(a, b) returns true because the latest a value is 5 and the latest b value is 6
-func Crossover(a, b Series) bool {
+func Crossover(a, b *Series) bool {
 	return a.Float(-1) > b.Float(-1) && a.Float(-2) <= b.Float(-2)
 }
 
+func CrossoverIndex[I comparable](index I, a, b *IndexedSeries[I]) bool {
+	aRow, bRow := a.Row(index), b.Row(index)
+	if aRow < 1 || bRow < 1 {
+		return false
+	}
+	return a.Float(aRow) > b.Float(bRow) && a.Float(aRow-1) <= b.Float(bRow-1)
+}
+
 // EasyIndex returns an index to the `n` -length object that allows for negative indexing. For example, EasyIndex(-1, 5) returns 4. This is similar to Python's negative indexing. The return value may be less than zero if (-i) > n.
 func EasyIndex(i, n int) int {
 	if i < 0 {