diff --git a/contracts/price-oracle/src/lib.rs b/contracts/price-oracle/src/lib.rs
index fdc6358..41189a4 100644
--- a/contracts/price-oracle/src/lib.rs
+++ b/contracts/price-oracle/src/lib.rs
@@ -444,6 +444,15 @@ pub struct BypassDisabledEvent {
     pub admin: Address,
 }
 
+// New event for logging price variance (percentage change in basis points)
+#[soroban_sdk::contractevent]
+pub struct PriceVarianceEvent {
+    pub asset: Symbol,
+    pub old_price: i128,
+    pub new_price: i128,
+    pub variance_bps: i128,
+}
+
 /// Emitted when a relayer's staked collateral is slashed by governance.
 #[soroban_sdk::contractevent]
 pub struct SlashExecutedEvent {
@@ -1101,6 +1110,10 @@ impl PriceOracle {
     ///
     /// Returns `Error::AssetNotFound` when the asset is missing or stale.
     pub fn get_price(env: Env, asset: Symbol, verified: bool) -> Result<PriceData, Error> {
+        // Reentrancy guard: reject calls during a locked set_price
+        if env.storage().temporary().get(&DataKey::IsLocked).unwrap_or(false) {
+            panic_with_error!(&env, Error::ReentrancyDetected);
+        }
         if crate::auth::_is_halted(&env) {
             panic_with_error!(&env, Error::EmergencyHalted);
         }
@@ -1127,6 +1140,10 @@ impl PriceOracle {
     /// Returns the last known price data and marks it stale when TTL has expired.
     /// Always reads from the `VerifiedPrice` bucket.
     pub fn get_price_with_status(env: Env, asset: Symbol) -> Result<PriceDataWithStatus, Error> {
+        // Reentrancy guard
+        if env.storage().temporary().get(&DataKey::IsLocked).unwrap_or(false) {
+            panic_with_error!(&env, Error::ReentrancyDetected);
+        }
         if crate::auth::_is_halted(&env) {
             panic_with_error!(&env, Error::EmergencyHalted);
         }
@@ -1149,6 +1166,10 @@ impl PriceOracle {
     /// Returns `None` instead of an error when the asset is not found.
     /// Always reads from the `VerifiedPrice` bucket.
     pub fn get_price_safe(env: Env, asset: Symbol) -> Option<PriceData> {
+        // Reentrancy guard
+        if env.storage().temporary().get(&DataKey::IsLocked).unwrap_or(false) {
+            panic_with_error!(&env, Error::ReentrancyDetected);
+        }
         if crate::auth::_is_halted(&env) {
             panic_with_error!(&env, Error::EmergencyHalted);
         }
@@ -1162,6 +1183,10 @@ impl PriceOracle {
     /// Always reads from the `VerifiedPrice` bucket.
     /// Returns the price value as an i128, or an error if the asset is not found.
     pub fn get_last_price(env: Env, asset: Symbol) -> Result<i128, Error> {
+        // Reentrancy guard
+        if env.storage().temporary().get(&DataKey::IsLocked).unwrap_or(false) {
+            panic_with_error!(&env, Error::ReentrancyDetected);
+        }
         if crate::auth::_is_halted(&env) {
             panic_with_error!(&env, Error::EmergencyHalted);
         }
@@ -1225,6 +1250,10 @@ impl PriceOracle {
         env: Env,
         assets: soroban_sdk::Vec<Symbol>,
     ) -> soroban_sdk::Vec<Option<PriceEntryWithStatus>> {
+        // Reentrancy guard
+        if env.storage().temporary().get(&DataKey::IsLocked).unwrap_or(false) {
+            panic_with_error!(&env, Error::ReentrancyDetected);
+        }
         let now = env.ledger().timestamp();
         let mut result = soroban_sdk::Vec::new(&env);
 
@@ -1324,6 +1353,7 @@ impl PriceOracle {
             let storage = env.storage().persistent();
             let key = DataKey::VerifiedPrice(asset.clone());
             let existing: Option<PriceData> = storage.get(&key);
+            let old_price_opt = existing.as_ref().map(|p| p.price);
             let is_new_asset = existing.is_none();
 
             _track_asset(&env, asset.clone());
@@ -1380,6 +1410,17 @@ impl PriceOracle {
                     price: normalized,
                 });
             }
+            // Emit variance event for price change
+            if let Some(old_price) = old_price_opt {
+                let variance_opt = calculate_percentage_change_bps(old_price, normalized);
+                env.events().publish_event(&PriceVarianceEvent {
+                    asset: asset.clone(),
+                    old_price,
+                    new_price: normalized,
+                    variance_bps: variance_opt.unwrap_or(0),
+                });
+                log_event(&env, Symbol::new(&env, "price_variance"), asset.clone(), variance_opt.unwrap_or(0));
+            }
 
             // Notify subscribers of the price update
             let payload = PriceUpdatePayload {
@@ -1417,6 +1458,10 @@ impl PriceOracle {
         decimals: u32,
         ttl: u64,
     ) -> Result<(), Error> {
+        // Reentrancy guard
+        if env.storage().temporary().get(&DataKey::IsLocked).unwrap_or(false) {
+            panic_with_error!(&env, Error::ReentrancyDetected);
+        }
         crate::auth::_require_not_frozen(&env);
         source.require_auth();
 
@@ -1545,6 +1590,14 @@ impl PriceOracle {
     /// This function operates on the `DataKey::Price(Symbol)` composite key used
     /// by snapshot tests and migration tooling. It does **not** touch
     /// `VerifiedPrice` or `CommunityPrice` buckets; use `remove_asset` for that.
+    pub fn get_index_price(env: Env, components: soroban_sdk::Vec<AssetWeight>) -> Result<i128, Error> {
+        // Reentrancy guard
+        if env.storage().temporary().get(&DataKey::IsLocked).unwrap_or(false) {
+            panic_with_error!(&env, Error::ReentrancyDetected);
+        }
+        // ... (existing logic)
+    }
+
     pub fn clear_assets(env: Env, assets: soroban_sdk::Vec<Symbol>) -> Result<(), Error> {
         if assets.len() > MAX_CLEAR_ASSETS {
             return Err(Error::TooManyAssets);
@@ -1780,6 +1833,10 @@ impl PriceOracle {
 
     /// Get the configured absolute floor price for an asset, if any.
     pub fn get_price_floor(env: Env, asset: Symbol) -> Option<i128> {
+        // Reentrancy guard
+        if env.storage().temporary().get(&DataKey::IsLocked).unwrap_or(false) {
+            panic_with_error!(&env, Error::ReentrancyDetected);
+        }
         read_price_floor(&env, &asset)
     }
 
@@ -1851,6 +1908,10 @@ impl PriceOracle {
 
     /// Get the current min/max price bounds for an asset, if configured.
     pub fn get_price_bounds(env: Env, asset: Symbol) -> Option<PriceBounds> {
+        // Reentrancy guard
+        if env.storage().temporary().get(&DataKey::IsLocked).unwrap_or(false) {
+            panic_with_error!(&env, Error::ReentrancyDetected);
+        }
         // Composite key: read only the single per-asset slot.
         env.storage()
             .persistent()
@@ -2760,6 +2821,10 @@ impl PriceOracle {
     /// Returns all relayer submissions for the current ledger,
     /// allowing consumers to see the individual inputs before median calculation.
     pub fn get_price_buffer_data(env: Env, asset: Symbol) -> Option<PriceBuffer> {
+        // Reentrancy guard
+        if env.storage().temporary().get(&DataKey::IsLocked).unwrap_or(false) {
+            panic_with_error!(&env, Error::ReentrancyDetected);
+        }
         let buffer = get_price_buffer(&env, asset);
         if buffer.entries.len() == 0 {
             return None;
@@ -2777,6 +2842,10 @@ impl PriceOracle {
 
     /// Get the Time-Weighted Average Price (TWAP) for a specific asset.
     pub fn get_twap(env: Env, asset: Symbol) -> Option<i128> {
+        // Reentrancy guard
+        if env.storage().temporary().get(&DataKey::IsLocked).unwrap_or(false) {
+            panic_with_error!(&env, Error::ReentrancyDetected);
+        }
         if crate::auth::_is_halted(&env) {
             panic_with_error!(&env, Error::EmergencyHalted);
         }
@@ -2830,6 +2899,10 @@ impl PriceOracle {
     /// # Returns
     /// A vector of addresses of all contracts currently subscribed to price updates.
     pub fn get_price_update_subscribers(env: Env) -> soroban_sdk::Vec<Address> {
+        // Reentrancy guard
+        if env.storage().temporary().get(&DataKey::IsLocked).unwrap_or(false) {
+            panic_with_error!(&env, Error::ReentrancyDetected);
+        }
         callbacks::get_subscribers(&env)
     }