diff --git a/121_best_time_to_buy_and_sell_stock/main.cpp b/121_best_time_to_buy_and_sell_stock/main.cpp
new file mode 100644
index 0000000..f528370
--- /dev/null
+++ b/121_best_time_to_buy_and_sell_stock/main.cpp
@@ -0,0 +1,19 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class Solution {
+   public:
+    int maxProfit(vector<int>& prices) {
+        int result = 0;
+        int minBuyPrice = prices[0];
+
+        for (int i = 1; i < prices.size(); i++) {
+            int sellPrice = prices[i];
+            int profit = sellPrice - minBuyPrice;
+            minBuyPrice = min(minBuyPrice, sellPrice);
+            result = max(result, profit);
+        }
+
+        return result;
+    }
+};