diff --git a/services/integration_tests/tests/common/auth_helpers.rs b/services/integration_tests/tests/common/auth_helpers.rs
index 8ac471000..8af44a23f 100644
--- a/services/integration_tests/tests/common/auth_helpers.rs
+++ b/services/integration_tests/tests/common/auth_helpers.rs
@@ -213,8 +213,10 @@ impl TestAuthConfig {
 /// 2. Set JWT_SECRET in .env file
 /// 3. Load .env before running tests (e.g., `source .env` or use dotenv)
 pub fn get_test_jwt_secret() -> String {
-    std::env::var("JWT_SECRET").expect(
-        "FATAL: JWT_SECRET must be set in .env file for E2E tests\n\
+    // WAVE 149 Agent 411: Trim whitespace to match API Gateway behavior
+    std::env::var("JWT_SECRET")
+        .expect(
+            "FATAL: JWT_SECRET must be set in .env file for E2E tests\n\
          \n\
          Setup:\n\
          1. Copy .env.example to .env\n\
@@ -222,7 +224,9 @@ pub fn get_test_jwt_secret() -> String {
          3. Run: export $(cat .env | xargs)\n\
          \n\
          Example: JWT_SECRET=OvFLDUbIDak3CSCi5t6zKfsAp65cjTOJ85q9YE+TFY8b361DGg1gSTra2rW6mps3cWrRGQ/NXRA5uftUpMldvOaEHMMgfBs4JjVODDElREdvUFm0EttD1A==",
-    )
+        )
+        .trim()
+        .to_string()
 }
 
 /// Get test user ID (consistent across tests)
@@ -492,6 +496,7 @@ mod tests {
     }
 
     #[test]
+    #[serial_test::serial]  // WAVE 149 Agent 415: Prevent test pollution from remove_var
     #[should_panic(expected = "JWT_SECRET must be set")]
     fn test_get_test_jwt_secret_fails_without_env() {
         // Clear JWT_SECRET to test fail-fast behavior
diff --git a/services/trading_service/tests/auth_security_tests.rs b/services/trading_service/tests/auth_security_tests.rs
index a3d33cb3e..f08656816 100644
--- a/services/trading_service/tests/auth_security_tests.rs
+++ b/services/trading_service/tests/auth_security_tests.rs
@@ -435,6 +435,7 @@ async fn test_jwt_token_with_all_role_types() -> Result<()> {
 // These tests verify the behavior through the public API
 
 #[test]
+#[serial_test::serial]  // WAVE 149 Agent 415: Prevent test pollution from remove_var
 fn test_jwt_secret_valid_strong_secret() {
     std::env::set_var("JWT_SECRET", TEST_JWT_SECRET);
     let result = AuthConfig::new();
@@ -443,6 +444,7 @@ fn test_jwt_secret_valid_strong_secret() {
 }
 
 #[test]
+#[serial_test::serial]  // WAVE 149 Agent 415: Prevent test pollution from remove_var
 fn test_jwt_secret_too_short_rejected() {
     let short_secret = "TooShort123!@#"; // Only 14 chars, needs 64
     std::env::set_var("JWT_SECRET", short_secret);
@@ -453,6 +455,7 @@ fn test_jwt_secret_too_short_rejected() {
 }
 
 #[test]
+#[serial_test::serial]  // WAVE 149 Agent 415: Prevent test pollution from remove_var
 fn test_jwt_secret_too_long_rejected() {
     let long_secret = "a".repeat(2000); // >1024 chars
     std::env::set_var("JWT_SECRET", &long_secret);
@@ -463,6 +466,7 @@ fn test_jwt_secret_too_long_rejected() {
 }
 
 #[test]
+#[serial_test::serial]  // WAVE 149 Agent 415: Prevent test pollution from remove_var
 fn test_jwt_secret_no_lowercase_rejected() {
     let no_lowercase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()ABCDEFGHIJKLMNOPQR";
     std::env::set_var("JWT_SECRET", no_lowercase);
@@ -473,6 +477,7 @@ fn test_jwt_secret_no_lowercase_rejected() {
 }
 
 #[test]
+#[serial_test::serial]  // WAVE 149 Agent 415: Prevent test pollution from remove_var
 fn test_jwt_secret_no_uppercase_rejected() {
     let no_uppercase = "abcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*()abcdefghijklmnopqr";
     std::env::set_var("JWT_SECRET", no_uppercase);
@@ -483,6 +488,7 @@ fn test_jwt_secret_no_uppercase_rejected() {
 }
 
 #[test]
+#[serial_test::serial]  // WAVE 149 Agent 415: Prevent test pollution from remove_var
 fn test_jwt_secret_no_digits_rejected() {
     let no_digits = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!@#$%^&*()";
     std::env::set_var("JWT_SECRET", no_digits);
@@ -493,6 +499,7 @@ fn test_jwt_secret_no_digits_rejected() {
 }
 
 #[test]
+#[serial_test::serial]  // WAVE 149 Agent 415: Prevent test pollution from remove_var
 fn test_jwt_secret_no_symbols_rejected() {
     let no_symbols = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
     std::env::set_var("JWT_SECRET", no_symbols);
@@ -503,6 +510,7 @@ fn test_jwt_secret_no_symbols_rejected() {
 }
 
 #[test]
+#[serial_test::serial]  // WAVE 149 Agent 415: Prevent test pollution from remove_var
 fn test_jwt_secret_repeated_characters_rejected() {
     let repeated = "Aaaaa1!Aaaaa1!Aaaaa1!Aaaaa1!Aaaaa1!Aaaaa1!Aaaaa1!Aaaaa1!Aaaaa1!"; // >3 repeated 'a'
     std::env::set_var("JWT_SECRET", repeated);
@@ -513,6 +521,7 @@ fn test_jwt_secret_repeated_characters_rejected() {
 }
 
 #[test]
+#[serial_test::serial]  // WAVE 149 Agent 415: Prevent test pollution from remove_var
 fn test_jwt_secret_sequential_pattern_rejected() {
     let sequential = "abcd1234ABCD!@#$abcd1234ABCD!@#$abcd1234ABCD!@#$abcd1234ABCD!";
     std::env::set_var("JWT_SECRET", sequential);
@@ -523,6 +532,7 @@ fn test_jwt_secret_sequential_pattern_rejected() {
 }
 
 #[test]
+#[serial_test::serial]  // WAVE 149 Agent 415: Prevent test pollution from remove_var
 fn test_jwt_secret_weak_dictionary_words_rejected() {
     let dictionary = "Password123!Password123!Password123!Password123!Password123!Pass";
     std::env::set_var("JWT_SECRET", dictionary);
@@ -533,6 +543,7 @@ fn test_jwt_secret_weak_dictionary_words_rejected() {
 }
 
 #[test]
+#[serial_test::serial]  // WAVE 149 Agent 415: Prevent test pollution from remove_var
 fn test_jwt_secret_low_entropy_rejected() {
     // Repetitive pattern with low entropy
     let low_entropy = "A1!a".repeat(20); // Repeating 4-char pattern
@@ -544,6 +555,7 @@ fn test_jwt_secret_low_entropy_rejected() {
 }
 
 #[test]
+#[serial_test::serial]  // WAVE 149 Agent 415: Prevent test pollution from remove_var
 fn test_jwt_secret_load_from_file_priority() {
     // Test JWT_SECRET_FILE takes priority over JWT_SECRET
     let temp_dir = std::env::temp_dir();