diff --git a/backend/seed.py b/backend/seed.py
index c9cd64c..8959c23 100644
--- a/backend/seed.py
+++ b/backend/seed.py
@@ -88,10 +88,11 @@ async def seed_pricing_config(db: AsyncSession) -> None:
     with constants_path.open() as f:
         constants = json.load(f)
 
-    exchange_config = constants["exchange"]
-    premium_percentage = exchange_config["premiumPercentage"]
-    eur_trade_min = exchange_config["eurTradeMin"]
-    eur_trade_max = exchange_config["eurTradeMax"]
+    exchange_config = constants.get("exchange", {})
+    # Use defaults if fields don't exist (for backward compatibility during migration)
+    premium_percentage = exchange_config.get("premiumPercentage", 5)
+    eur_trade_min = exchange_config.get("eurTradeMin", 100)
+    eur_trade_max = exchange_config.get("eurTradeMax", 3000)
 
     # Convert EUR amounts to cents
     eur_min_cents = eur_trade_min * 100
diff --git a/backend/seed_e2e.py b/backend/seed_e2e.py
index 70bbfee..f0f0424 100644
--- a/backend/seed_e2e.py
+++ b/backend/seed_e2e.py
@@ -103,10 +103,11 @@ async def seed_base_data(db: AsyncSession) -> None:
     with constants_path.open() as f:
         constants = json.load(f)
 
-    exchange_config = constants["exchange"]
-    premium_percentage = exchange_config["premiumPercentage"]
-    eur_trade_min = exchange_config["eurTradeMin"]
-    eur_trade_max = exchange_config["eurTradeMax"]
+    exchange_config = constants.get("exchange", {})
+    # Use defaults if fields don't exist (for backward compatibility during migration)
+    premium_percentage = exchange_config.get("premiumPercentage", 5)
+    eur_trade_min = exchange_config.get("eurTradeMin", 100)
+    eur_trade_max = exchange_config.get("eurTradeMax", 3000)
 
     # Convert EUR amounts to cents
     eur_min_cents = eur_trade_min * 100
diff --git a/backend/shared_constants.py b/backend/shared_constants.py
index 2950fff..e2055f2 100644
--- a/backend/shared_constants.py
+++ b/backend/shared_constants.py
@@ -10,10 +10,7 @@ _constants = json.loads(_constants_path.read_text())
 SLOT_DURATION_MINUTES: int = _constants["exchange"]["slotDurationMinutes"]
 MIN_ADVANCE_DAYS: int = _constants["exchange"]["minAdvanceDays"]
 MAX_ADVANCE_DAYS: int = _constants["exchange"]["maxAdvanceDays"]
-EUR_TRADE_MIN: int = _constants["exchange"]["eurTradeMin"]
-EUR_TRADE_MAX: int = _constants["exchange"]["eurTradeMax"]
 EUR_TRADE_INCREMENT: int = _constants["exchange"]["eurTradeIncrement"]
-PREMIUM_PERCENTAGE: int = _constants["exchange"]["premiumPercentage"]
 PRICE_REFRESH_SECONDS: int = _constants["exchange"]["priceRefreshSeconds"]
 PRICE_STALENESS_SECONDS: int = _constants["exchange"]["priceStalenessSeconds"]
 LIGHTNING_MAX_EUR: int = _constants["exchange"]["lightningMaxEur"]
diff --git a/backend/tests/test_pricing_repository.py b/backend/tests/test_pricing_repository.py
index 3cc1b1b..f273a08 100644
--- a/backend/tests/test_pricing_repository.py
+++ b/backend/tests/test_pricing_repository.py
@@ -176,10 +176,11 @@ class TestPricingSeeding:
         with constants_path.open() as f:
             constants = json.load(f)
 
-        exchange_config = constants["exchange"]
-        expected_premium = exchange_config["premiumPercentage"]
-        expected_min_eur = exchange_config["eurTradeMin"]
-        expected_max_eur = exchange_config["eurTradeMax"]
+        exchange_config = constants.get("exchange", {})
+        # Use defaults if fields don't exist (they may have been removed)
+        expected_premium = exchange_config.get("premiumPercentage", 5)
+        expected_min_eur = exchange_config.get("eurTradeMin", 100)
+        expected_max_eur = exchange_config.get("eurTradeMax", 3000)
 
         async with client_factory.get_db_session() as db:
             # Replicate seed_pricing_config logic without importing seed.py
@@ -217,10 +218,11 @@ class TestPricingSeeding:
         with constants_path.open() as f:
             constants = json.load(f)
 
-        exchange_config = constants["exchange"]
-        expected_premium = exchange_config["premiumPercentage"]
-        expected_min_eur = exchange_config["eurTradeMin"]
-        expected_max_eur = exchange_config["eurTradeMax"]
+        exchange_config = constants.get("exchange", {})
+        # Use defaults if fields don't exist (they may have been removed)
+        expected_premium = exchange_config.get("premiumPercentage", 5)
+        expected_min_eur = exchange_config.get("eurTradeMin", 100)
+        expected_max_eur = exchange_config.get("eurTradeMax", 3000)
 
         async with client_factory.get_db_session() as db:
             repo = PricingRepository(db)
diff --git a/backend/validate_constants.py b/backend/validate_constants.py
index dc7b6a4..f8f90e7 100644
--- a/backend/validate_constants.py
+++ b/backend/validate_constants.py
@@ -75,10 +75,7 @@ def validate_shared_constants() -> None:
         "slotDurationMinutes",
         "maxAdvanceDays",
         "minAdvanceDays",
-        "eurTradeMin",
-        "eurTradeMax",
         "eurTradeIncrement",
-        "premiumPercentage",
         "priceRefreshSeconds",
         "priceStalenessSeconds",
         "lightningMaxEur",
diff --git a/shared/constants.json b/shared/constants.json
index 4e1615d..e930667 100644
--- a/shared/constants.json
+++ b/shared/constants.json
@@ -27,10 +27,7 @@
     "slotDurationMinutes": 15,
     "maxAdvanceDays": 30,
     "minAdvanceDays": 1,
-    "eurTradeMin": 100,
-    "eurTradeMax": 3000,
     "eurTradeIncrement": 20,
-    "premiumPercentage": 5,
     "priceRefreshSeconds": 60,
     "priceStalenessSeconds": 300,
     "lightningMaxEur": 1000