diff --git a/foundry/balance-drop-trap/foundry.toml b/foundry/balance-drop-trap/foundry.toml
new file mode 100644
index 0000000..4b65823
--- /dev/null
+++ b/foundry/balance-drop-trap/foundry.toml
@@ -0,0 +1,8 @@
+[profile.default]
+src = 'src'
+test = 'test'
+libs = ['../../node_modules']
+remappings = [
+    'drosera-contracts/=../../node_modules/contracts/src/',
+    'forge-std/=../../node_modules/forge-std/src/'
+]
diff --git a/foundry/balance-drop-trap/src/BalanceDropTrap.sol b/foundry/balance-drop-trap/src/BalanceDropTrap.sol
new file mode 100644
index 0000000..39d3be8
--- /dev/null
+++ b/foundry/balance-drop-trap/src/BalanceDropTrap.sol
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+import {ITrap} from "drosera-contracts/interfaces/ITrap.sol";
+
+// This trap detects sudden drops in the ETH balance of a specific wallet.
+contract BalanceDropTrap is ITrap {
+    // The wallet address to monitor (Example: Vitalik Buterin's address)
+    address constant TARGET_WALLET = 0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B;
+    
+    // Using BPS for finer control (10,000 = 100%)
+    uint256 constant BPS = 10_000;
+    uint256 constant THRESHOLD_BPS = 5_000; // 50% threshold
+
+    // This function runs on every block and records the wallet's current ETH balance.
+    function collect() external view override returns (bytes memory) {
+        // Including block.number for easier debugging as suggested
+        return abi.encode(block.number, TARGET_WALLET.balance);
+    }
+
+    // This function analyzes the data from past blocks.
+    function shouldRespond(bytes[] calldata data) external pure override returns (bool, bytes memory) {
+        // At least 2 blocks of data are needed for analysis.
+        if (data.length < 2) {
+            return (false, bytes(""));
+        }
+
+        // Drosera passes samples newest first: data[0] is current, data[1] is previous.
+        ( , uint256 currentBalance) = abi.decode(data[0], (uint256, uint256));
+        ( , uint256 previousBalance) = abi.decode(data[1], (uint256, uint256));
+        
+        // If the balance has not dropped or the previous balance was 0, there is no issue.
+        if (currentBalance >= previousBalance || previousBalance == 0) {
+            return (false, bytes(""));
+        }
+
+        // Calculate the drop amount and percentage in BPS.
+        uint256 dropBps = ((previousBalance - currentBalance) * BPS) / previousBalance;
+
+        // If the drop is greater than our threshold, TRIGGER THE ALARM!
+        if (dropBps >= THRESHOLD_BPS) {
+            return (true, abi.encode(previousBalance, currentBalance));
+        }
+
+        // If the drop is less than the threshold, there is no issue.
+        return (false, bytes(""));
+    }
+}
diff --git a/foundry/balance-drop-trap/test/BalanceDropTrap.t.sol b/foundry/balance-drop-trap/test/BalanceDropTrap.t.sol
new file mode 100644
index 0000000..a0bfd39
--- /dev/null
+++ b/foundry/balance-drop-trap/test/BalanceDropTrap.t.sol
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+import {Test} from "forge-std/Test.sol";
+import {BalanceDropTrap} from "../../src/BalanceDropTrap.sol";
+
+// Test kontratımız, Foundry'nin Test kontratından miras alır.
+contract BalanceDropTrapTest is Test {
+    BalanceDropTrap public trap;
+
+    // Bu fonksiyon, her testten önce çalışır ve tuzağımızı kurar.
+    function setUp() public {
+        trap = new BalanceDropTrap();
+    }
+
+    // Bu test, bakiye %50'den fazla düştüğünde tuzağın alarm vermesi gerektiğini doğrular.
+    function testShouldRespondOnSignificantDrop() public {
+        // Geçmiş verileri simüle ediyoruz.
+        bytes[] memory data = new bytes[](2);
+        
+        // Önceki bakiye: 100 ETH
+        data[0] = abi.encode(100 ether);
+        // Şimdiki bakiye: 40 ETH (yani %60'lık bir düşüş)
+        data[1] = abi.encode(40 ether);
+
+        // Tuzağımızın shouldRespond fonksiyonunu bu sahte verilerle çağırıyoruz.
+        (bool should, ) = trap.shouldRespond(data);
+
+        // Sonucun 'true' olmasını bekliyoruz ve bunu doğruluyoruz.
+        assertTrue(should, "Trap should respond on a >50% balance drop");
+    }
+
+    // Bu test, bakiye %50'den az düştüğünde tuzağın alarm VERMEMESİ gerektiğini doğrular.
+    function testShouldNotRespondOnInsignificantDrop() public {
+        bytes[] memory data = new bytes[](2);
+        
+        // Önceki bakiye: 100 ETH
+        data[0] = abi.encode(100 ether);
+        // Şimdiki bakiye: 80 ETH (yani %20'lik bir düşüş)
+        data[1] = abi.encode(80 ether);
+
+        (bool should, ) = trap.shouldRespond(data);
+
+        // Sonucun 'false' olmasını bekliyoruz ve bunu doğruluyoruz.
+        assertFalse(should, "Trap should NOT respond on a <50% balance drop");
+    }
+}