diff --git a/target/test-classes/ExchangeTest.java b/src/test/java/ExchangeTest.java
similarity index 88%
rename from target/test-classes/ExchangeTest.java
rename to src/test/java/ExchangeTest.java
index d3bcd62..eb3ad47 100644
--- a/target/test-classes/ExchangeTest.java
+++ b/src/test/java/ExchangeTest.java
@@ -1,19 +1,18 @@
-import static org.junit.Assert.assertEquals;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
 
 import java.math.BigDecimal;
 import java.util.ArrayList;
 import java.util.List;
 
-import org.junit.Before;
-import org.junit.Test;
-
 public class ExchangeTest {
 
     private Exchange exchange;
     private Stock apple;
     private Stock google;
 
-    @Before
+    @BeforeAll
     public void setUp() {
         apple = new Stock("AAPL", "Apple", new BigDecimal("100"));
         google = new Stock("GOOGL", "Google", new BigDecimal("200"));
diff --git a/src/test/java/PortfolioTest.java b/src/test/java/PortfolioTest.java
new file mode 100644
index 0000000..36f7419
--- /dev/null
+++ b/src/test/java/PortfolioTest.java
@@ -0,0 +1,83 @@
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+import java.math.BigDecimal;
+
+public class PortfolioTest {
+
+    @Test
+    void testAddSharePortfolio() {
+        Portfolio portfolio = new Portfolio();
+
+        Stock stock = new Stock("AAPL", "Apple", new BigDecimal("150"));
+        Share share = new Share(stock, new BigDecimal("10"), new BigDecimal("140"));
+
+        boolean result = portfolio.addShare(share);
+
+        assertTrue(result);
+        assertTrue(portfolio.contains(share));
+    }
+
+    @Test
+    void testRemoveSharePortfolio() {
+        Portfolio portfolio = new Portfolio();
+
+        Stock stock = new Stock("AAPL", "Apple", new BigDecimal("150"));
+        Share share = new Share(stock, new BigDecimal("10"), new BigDecimal("140"));
+
+        portfolio.addShare(share);
+
+        boolean result = portfolio.removeShare(share);
+
+        assertTrue(result);
+        assertFalse(portfolio.contains(share));
+    }
+
+    @Test
+    void testGetSharesPortfolio() {
+        Portfolio portfolio = new Portfolio();
+
+        Stock stock = new Stock("AAPL", "Apple", new BigDecimal("150"));
+        Share share = new Share(stock, new BigDecimal("10"), new BigDecimal("140"));
+
+        portfolio.addShare(share);
+
+        var shares = portfolio.getShares();
+
+        assertEquals(1, shares.size());
+        assertTrue(shares.contains(share));
+    }
+
+    @Test
+    void testGetSharesBySymbolPortfolio() {
+        Portfolio portfolio = new Portfolio();
+
+        Stock stock1 = new Stock("AAPL", "Apple", new BigDecimal("150"));
+        Stock stock2 = new Stock("GOOGL", "Google", new BigDecimal("200"));
+
+        Share share1 = new Share(stock1, new BigDecimal("10"), new BigDecimal("140"));
+        Share share2 = new Share(stock2, new BigDecimal("10"), new BigDecimal("190"));
+
+        portfolio.addShare(share1);
+        portfolio.addShare(share2);
+
+        var result = portfolio.getShares("AAPL");
+
+        assertEquals(1, result.size());
+        assertTrue(result.contains(share1));
+    }
+
+    @Test
+    void testContainsPortfolio() {
+        Portfolio portfolio = new Portfolio();
+
+        Stock stock = new Stock("AAPL", "Apple", new BigDecimal("150"));
+        Share share = new Share(stock, new BigDecimal("10"), new BigDecimal("140"));
+
+        portfolio.addShare(share);
+
+        assertTrue(portfolio.contains(share));
+    }
+
+    
+}
diff --git a/src/test/java/ShareTest.java b/src/test/java/ShareTest.java
new file mode 100644
index 0000000..ba6dc76
--- /dev/null
+++ b/src/test/java/ShareTest.java
@@ -0,0 +1,71 @@
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+import java.math.BigDecimal;
+
+
+public class ShareTest {
+
+    @Test
+    void testShareConstructor() {
+
+        Stock stock = new Stock("AAPL", "Apple", new BigDecimal("150"));
+        BigDecimal quantity = new BigDecimal("10");
+        BigDecimal purchasePrice = new BigDecimal("140");
+
+        Share share = new Share(stock, quantity, purchasePrice);
+        assertNotNull(share);
+    }
+
+    @Test
+    void testGetStock() {
+
+        Stock stock = new Stock("AAPL", "Apple", new BigDecimal("150"));
+        Share share = new Share(stock, new BigDecimal("10"), new BigDecimal("140"));
+
+        Stock result = share.getStock();
+
+        assertEquals(stock, result);
+    }
+
+    @Test
+    void testGetQuantity() {
+
+        Stock stock = new Stock("AAPL", "Apple", new BigDecimal("150"));
+        Share share = new Share(stock, new BigDecimal("10"), new BigDecimal("140"));
+
+        BigDecimal result = share.getQuantity();
+
+        assertEquals(new BigDecimal("10"), result);
+    }
+
+    @Test
+    void testGetPurchasePrice() {
+
+        Stock stock = new Stock("AAPL", "Apple", new BigDecimal("150"));
+        Share share = new Share(stock, new BigDecimal("10"), new BigDecimal("140"));
+
+        BigDecimal result = share.getPurchasePrice();
+
+        assertEquals(new BigDecimal("140"), result);
+    }
+
+    @Test
+    void testNullStock() {
+
+        Share share = new Share(null, new BigDecimal("10"), new BigDecimal("100"));
+
+        assertNull(share.getStock());
+    }
+
+    @Test
+    void testNegativePrice() {
+
+        Stock stock = new Stock("AAPL", "Apple", new BigDecimal("150"));
+        Share share = new Share(stock, new BigDecimal("10"), new BigDecimal("-50"));
+
+        assertEquals(new BigDecimal("-50"), share.getPurchasePrice());
+    }
+
+    
+}
diff --git a/target/test-classes/StockTest.java b/src/test/java/StockTest.java
similarity index 92%
rename from target/test-classes/StockTest.java
rename to src/test/java/StockTest.java
index 5f587f9..1bfcc2a 100644
--- a/target/test-classes/StockTest.java
+++ b/src/test/java/StockTest.java
@@ -1,9 +1,8 @@
-import static org.junit.Assert.assertEquals;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
 
 import java.math.BigDecimal;
 
-import org.junit.Test;
-
 
 public class StockTest {
 
diff --git a/target/classes/PurchaseCalculator.class b/target/classes/PurchaseCalculator.class
index c50d57d..bab65f2 100644
Binary files a/target/classes/PurchaseCalculator.class and b/target/classes/PurchaseCalculator.class differ