diff --git a/src/indicator.rs b/src/indicator.rs
index 861ef9d..5a1ce1c 100644
--- a/src/indicator.rs
+++ b/src/indicator.rs
@@ -311,3 +311,62 @@ pub fn cvi(h: &[f64], l: &[f64], window: u8, rate_of_change: u8) -> Vec<f64> {
     .map(|w| 100.0 * (w.last().unwrap() / w.first().unwrap() - 1.0))
     .collect::<Vec<f64>>()
 }
+
+/// Williams Percent Range
+/// https://www.investopedia.com/terms/w/williamsr.asp
+pub fn wpr(h: &[f64], l: &[f64], c: &[f64], window: u8) -> Vec<f64> {
+    izip!(
+        h.windows(window.into()),
+        l.windows(window.into()),
+        &c[(window - 1).into()..]
+    )
+    .map(|(high, low, close)| {
+        let hh = high.iter().fold(f64::NAN, |state, &x| state.max(x));
+        let ll = low.iter().fold(f64::NAN, |state, &x| state.min(x));
+        -100.0 * ((hh - close) / (hh - ll))
+    })
+    .collect::<Vec<f64>>()
+}
+
+/// vortex
+/// https://www.investopedia.com/terms/v/vortex-indicator-vi.asp
+pub fn vortex(h: &[f64], l: &[f64], c: &[f64], window: u8) -> (Vec<f64>, Vec<f64>) {
+    izip!(
+        &h[..h.len() - 1],
+        &h[1..],
+        &l[..l.len() - 1],
+        &l[1..],
+        &c[..c.len() - 1],
+    )
+    .map(|(prevh, h, prevl, l, prevc)| {
+        let vm_pos = (h - prevl).abs();
+        let vm_neg = (l - prevh).abs();
+        let tr = (h - l).max(f64::abs(h - prevc)).max(f64::abs(l - prevc));
+        (vm_pos, vm_neg, tr)
+    })
+    .collect::<Vec<(f64, f64, f64)>>()
+    .windows(window.into())
+    .map(|w| {
+        let (vm_pos, vm_neg, tr) = w
+            .iter()
+            .copied()
+            .reduce(|(acc_pos, acc_neg, acc_tr), (pos, neg, tr)| {
+                (acc_pos + pos, acc_neg + neg, acc_tr + tr)
+            })
+            .unwrap();
+        (vm_pos / tr, vm_neg / tr)
+    })
+    .unzip()
+}
+
+/// percent oscillator
+/// pass in any data (close, high, low, etc...), and two window ranges
+pub fn po(data: &[f64], short: u8, long: u8) -> Vec<f64> {
+    let short_ma = smooth::ewma(&data, short);
+    let long_ma = smooth::ewma(&data, long);
+    short_ma[short_ma.len() - long_ma.len()..]
+        .iter()
+        .zip(long_ma)
+        .map(|(x, y)| 100.0 * (x / y - 1.0))
+        .collect::<Vec<f64>>()
+}
diff --git a/src/main.rs b/src/main.rs
index 1b4c276..ceb342f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -16,5 +16,5 @@ fn main() {
     let data = fs::read_to_string("./tests/rddt.input").expect("Unable to read file");
     let stats: SecStats = serde_json::from_str(&data).expect("JSON does not have correct format.");
 
-    dbg!(indicator::cvi(&stats.high, &stats.low, 16, 2));
+    dbg!(indicator::po(&stats.volume, 10, 16));
 }
diff --git a/tests/indicator_test.rs b/tests/indicator_test.rs
index 99fed5d..477e83b 100644
--- a/tests/indicator_test.rs
+++ b/tests/indicator_test.rs
@@ -564,3 +564,115 @@ fn test_cvi() {
         result
     );
 }
+
+#[test]
+fn test_wpr() {
+    let stats = common::test_data();
+    let result = indicator::wpr(&stats.high, &stats.low, &stats.close, 16);
+    assert_eq!(
+        vec![
+            -99.09142622449394,
+            -94.88476784384058,
+            -98.7016646516565,
+            -83.45322691468988,
+            -80.33424822308433,
+            -66.49998256138393,
+            -60.92856270926339,
+            -58.24332819489061,
+            -56.88925190670342,
+            -31.699065254207774,
+            -24.51395669497002,
+            -38.50825188642196,
+            -26.019074805435594,
+            -15.778329765623885,
+            -24.403940042613893,
+            -12.779540060870623,
+            -7.164869527394986,
+            -21.111723928174033,
+            -32.930944560522704,
+        ],
+        result
+    );
+}
+
+#[test]
+fn test_vortex() {
+    let stats = common::test_data();
+    let (vi_pos, vi_neg) = indicator::vortex(&stats.high, &stats.low, &stats.close, 16);
+    assert_eq!(
+        vec![
+            0.8610723090930696,
+            0.8159089697456218,
+            0.5782198030623583,
+            0.7200793857247078,
+            0.8358118890986928,
+            0.9355813847576413,
+            0.9484126915125689,
+            0.8489016637989781,
+            0.9131108818882286,
+            0.9790387062979787,
+            0.9343265196480259,
+            0.9443134085341751,
+            1.0302488811514465,
+            1.0364553935724832,
+            1.0553301509762798,
+            1.1219923299032897,
+            1.161732264987062,
+            1.1478332770638693,
+        ],
+        vi_pos
+    );
+    assert_eq!(
+        vec![
+            1.029701151945177,
+            1.1817046446451998,
+            1.3803206728528217,
+            1.238892593460365,
+            1.1850444607043855,
+            1.061167502645104,
+            1.111042759028416,
+            1.1313347365841422,
+            0.9951327158267141,
+            0.9280527122256887,
+            0.9901265627745084,
+            0.9313767804581332,
+            0.8402113281909229,
+            0.891932290028499,
+            0.8280623772231498,
+            0.7860652938018367,
+            0.6974842970716879,
+            0.7557323147066469,
+        ],
+        vi_neg
+    );
+}
+
+#[test]
+fn test_po() {
+    let stats = common::test_data();
+    let result = indicator::po(&stats.volume, 10, 16);
+    assert_eq!(
+        vec![
+            -35.378723807894985,
+            -37.993168058882375,
+            -39.524346350340444,
+            -40.41967020222986,
+            -40.51097271301698,
+            -42.086823387150005,
+            -42.30015209438188,
+            -43.383528771209576,
+            -43.81409605428357,
+            -40.648471039972534,
+            -37.7876496415686,
+            -37.39351505516741,
+            -37.136103488993875,
+            -34.28067604316157,
+            -35.12026222042619,
+            -32.44673522414948,
+            -18.294669010949182,
+            2.308566455542005,
+            -0.92080395315155,
+        ],
+        result
+    );
+}