diff --git a/best-time-to-buy-and-sell-stock/kimyoung.js b/best-time-to-buy-and-sell-stock/kimyoung.js
new file mode 100644
index 000000000..35518bcd1
--- /dev/null
+++ b/best-time-to-buy-and-sell-stock/kimyoung.js
@@ -0,0 +1,21 @@
+/**
+ * @param {number[]} prices
+ * @return {number}
+ */
+var maxProfit = function(prices) {
+    let left = 0, right = 1;
+    let max = 0;
+    
+    while(right < prices.length) {
+        if(prices[right] < prices[left]) {
+            left = right;
+        } else {
+            max = Math.max(max, prices[right] - prices[left]);
+        }
+        right++;
+    }
+    return max;
+};
+
+// time - O(n) iterate through prices once
+// space - O(1)