diff --git a/crates/fidc-core/src/data.rs b/crates/fidc-core/src/data.rs
index 65dbcd2..167cd77 100644
--- a/crates/fidc-core/src/data.rs
+++ b/crates/fidc-core/src/data.rs
@@ -2325,6 +2325,20 @@ impl DataSet {
         rows_by_symbol.into_values().map(|rows| rows.len()).sum()
     }
 
+    pub fn release_execution_quotes_on_date(&mut self, date: NaiveDate) -> usize {
+        let row_count = self
+            .execution_quotes_by_date
+            .get(&date)
+            .map(|rows_by_symbol| rows_by_symbol.values().map(Vec::len).sum())
+            .unwrap_or(0);
+        // Run data shares this immutable map with the prepared-data cache. Arc::make_mut here
+        // would clone every date just to remove one entry and would not release the cached base.
+        if row_count == 0 || Arc::strong_count(&self.execution_quotes_by_date) > 1 {
+            return row_count;
+        }
+        self.remove_execution_quotes_on_date(date)
+    }
+
     pub fn snapshot_components(&self) -> DataSetSnapshotComponents {
         let mut instruments = self.instruments.values().cloned().collect::<Vec<_>>();
         instruments.sort_by(|left, right| left.symbol.cmp(&right.symbol));
@@ -5705,6 +5719,54 @@ mod tests {
         assert_eq!(run_data.execution_quote_count(), 0);
     }
 
+    #[test]
+    fn shared_execution_quote_release_does_not_clone_the_base_map() {
+        let date = NaiveDate::parse_from_str("2025-01-02", "%Y-%m-%d").unwrap();
+        let quote = IntradayExecutionQuote {
+            date,
+            timestamp: NaiveDateTime::parse_from_str(
+                "2025-01-02 10:18:00",
+                "%Y-%m-%d %H:%M:%S",
+            )
+            .unwrap(),
+            symbol: "000001.SZ".to_string(),
+            last_price: 10.0,
+            bid1: 10.0,
+            ask1: 10.0,
+            bid1_volume: 10_000,
+            ask1_volume: 10_000,
+            volume_delta: 10_000,
+            amount_delta: 100_000.0,
+            trading_phase: Some("continuous".to_string()),
+        };
+        let data = DataSet::from_components_with_actions_and_quotes(
+            Vec::new(),
+            vec![market_row("2025-01-02", 10.0, 1_000_000)],
+            Vec::new(),
+            Vec::new(),
+            vec![benchmark_row("2025-01-02", 12.0)],
+            Vec::new(),
+            vec![quote],
+        )
+        .unwrap();
+        let mut run_data = data.clone();
+
+        assert!(Arc::ptr_eq(
+            &data.execution_quotes_by_date,
+            &run_data.execution_quotes_by_date
+        ));
+        assert_eq!(run_data.release_execution_quotes_on_date(date), 1);
+        assert!(Arc::ptr_eq(
+            &data.execution_quotes_by_date,
+            &run_data.execution_quotes_by_date
+        ));
+        assert_eq!(run_data.execution_quote_count(), 1);
+
+        drop(data);
+        assert_eq!(run_data.release_execution_quotes_on_date(date), 1);
+        assert_eq!(run_data.execution_quote_count(), 0);
+    }
+
     #[test]
     fn baseline_selection_uses_structured_instrument_dates_and_status_only() {
         let date = NaiveDate::parse_from_str("2025-01-02", "%Y-%m-%d").unwrap();
diff --git a/crates/fidc-core/src/engine.rs b/crates/fidc-core/src/engine.rs
index 5ea1c5a..3a6e6c5 100644
--- a/crates/fidc-core/src/engine.rs
+++ b/crates/fidc-core/src/engine.rs
@@ -3053,7 +3053,7 @@ where
                 drop(minute_group);
                 drop(minute_quotes);
                 drop(quote_data);
-                self.data.remove_execution_quotes_on_date(execution_date);
+                self.data.release_execution_quotes_on_date(execution_date);
             }
 
             portfolio.update_prices_with_options(