diff --git a/ta_lib/Cargo.lock b/ta_lib/Cargo.lock
index ef82fb33..7e1a772c 100644
--- a/ta_lib/Cargo.lock
+++ b/ta_lib/Cargo.lock
@@ -12,6 +12,14 @@ dependencies = [
 [[package]]
 name = "overlap"
 version = "0.1.0"
+dependencies = [
+ "price",
+ "statistics",
+]
+
+[[package]]
+name = "patterns"
+version = "0.1.0"
 
 [[package]]
 name = "price"
@@ -20,3 +28,7 @@ version = "0.1.0"
 [[package]]
 name = "statistics"
 version = "0.1.0"
+
+[[package]]
+name = "volatility"
+version = "0.1.0"
diff --git a/ta_lib/Cargo.toml b/ta_lib/Cargo.toml
index 9fa72d42..6ffba8dd 100644
--- a/ta_lib/Cargo.toml
+++ b/ta_lib/Cargo.toml
@@ -3,5 +3,7 @@ members = [
 "overlap",
 "momentum",
 "price",
-"statistics"
+"statistics",
+"volatility",
+"patterns"
 ]
diff --git a/ta_lib/momentum/src/rsi.rs b/ta_lib/momentum/src/rsi.rs
index 214e7aef..61a72524 100644
--- a/ta_lib/momentum/src/rsi.rs
+++ b/ta_lib/momentum/src/rsi.rs
@@ -1,12 +1,14 @@
 use overlap::smma::smma;
 
 pub fn rsi(data: &[f64], period: usize) -> Vec<Option<f64>> {
-    if data.len() < period {
-        return vec![None; data.len()];
+    let len = data.len();
+
+    if len < period {
+        return vec![None; len];
     }
 
-    let mut gains = vec![0.0; data.len()];
-    let mut losses = vec![0.0; data.len()];
+    let mut gains = vec![0.0; len];
+    let mut losses = vec![0.0; len];
 
     for i in 1..data.len() {
         let change = data[i] - data[i - 1];
diff --git a/ta_lib/overlap/src/ema.rs b/ta_lib/overlap/src/ema.rs
index f7cec8ea..459ced6f 100644
--- a/ta_lib/overlap/src/ema.rs
+++ b/ta_lib/overlap/src/ema.rs
@@ -1,16 +1,18 @@
 pub fn ema(data: &[f64], period: usize) -> Vec<Option<f64>> {
-    if data.len() < period {
-        return vec![None; data.len()];
+    let len = data.len();
+
+    if len < period {
+        return vec![None; len];
     }
 
     let alpha = 2.0 / (period as f64 + 1.0);
 
-    let mut ema = vec![None; data.len()];
-
+    let mut ema = vec![None; len];
     let mut ema_current = data[0];
 
-    for i in 1..data.len() {
+    for i in 1..len {
         ema_current = (data[i] - ema_current) * alpha + ema_current;
+
         if i >= period - 1 {
             ema[i] = Some(ema_current);
         }
diff --git a/ta_lib/overlap/src/lib.rs b/ta_lib/overlap/src/lib.rs
index 1a8ffebf..67eaec5e 100644
--- a/ta_lib/overlap/src/lib.rs
+++ b/ta_lib/overlap/src/lib.rs
@@ -2,3 +2,4 @@ pub mod ema;
 pub mod sma;
 pub mod smma;
 pub mod vwap;
+pub mod vama;
\ No newline at end of file
diff --git a/ta_lib/overlap/src/sma.rs b/ta_lib/overlap/src/sma.rs
index 61a445ac..df39a640 100644
--- a/ta_lib/overlap/src/sma.rs
+++ b/ta_lib/overlap/src/sma.rs
@@ -1,8 +1,14 @@
 pub fn sma(data: &[f64], period: usize) -> Vec<Option<f64>> {
-    let mut sma = vec![None; data.len()];
+    let len = data.len();
+
+    if len < period {
+        return vec![None; len];
+    }
+
+    let mut sma = vec![None; len];
     let mut sum = 0.0;
 
-    for i in 0..data.len() {
+    for i in 0..len {
         sum += data[i];
 
         if i >= period {
diff --git a/ta_lib/overlap/src/smma.rs b/ta_lib/overlap/src/smma.rs
index 682fffee..8891d852 100644
--- a/ta_lib/overlap/src/smma.rs
+++ b/ta_lib/overlap/src/smma.rs
@@ -1,16 +1,18 @@
 pub fn smma(data: &[f64], period: usize) -> Vec<Option<f64>> {
-    if data.len() < period {
-        return vec![None; data.len()];
+    let len = data.len();
+
+    if len < period {
+        return vec![None; len];
     }
 
     let alpha = 1.0 / period as f64;
 
-    let mut smma = vec![None; data.len()];
-
+    let mut smma = vec![None; len];
     let mut smma_current = data[0];
 
-    for i in 1..data.len() {
+    for i in 1..len {
         smma_current = (data[i] - smma_current) * alpha + smma_current;
+
         if i >= period - 1 {
             smma[i] = Some(smma_current);
         }