diff --git a/crates/fidc-core/src/platform_expr_strategy.rs b/crates/fidc-core/src/platform_expr_strategy.rs
index a896d33..cab6424 100644
--- a/crates/fidc-core/src/platform_expr_strategy.rs
+++ b/crates/fidc-core/src/platform_expr_strategy.rs
@@ -1052,9 +1052,8 @@ pub struct PlatformExprStrategy {
     stock_text_factors_required: bool,
     stock_state_cache_date: RefCell<Option<NaiveDate>>,
     stock_state_cache_calendar_index: RefCell<Option<usize>>,
-    stock_state_cache: RefCell<
-        AHashMap<(NaiveDate, NaiveDate, u32, Option<NaiveTime>, bool), Arc<StockExpressionState>>,
-    >,
+    stock_state_cache:
+        RefCell<AHashMap<(NaiveDate, u32, Option<NaiveTime>, bool), Arc<StockExpressionState>>>,
 }
 
 #[derive(Debug, Clone, PartialEq)]
@@ -4022,13 +4021,7 @@ impl PlatformExprStrategy {
             }
             *self.stock_state_cache_calendar_index.borrow()
         };
-        let cache_key = (
-            date,
-            factor_date,
-            symbol_id,
-            execution_time,
-            use_intraday_quote,
-        );
+        let cache_key = (factor_date, symbol_id, execution_time, use_intraday_quote);
         if let Some(state) = self.stock_state_cache.borrow().get(&cache_key) {
             return Ok(Arc::clone(state));
         }
@@ -12611,6 +12604,7 @@ fn code_number_value(value: &str) -> i64 {
 #[cfg(test)]
 mod tests {
     use std::collections::{BTreeMap, BTreeSet};
+    use std::sync::Arc;
 
     use chrono::{NaiveDate, NaiveTime};
 
@@ -12637,6 +12631,121 @@ mod tests {
         NaiveDate::from_ymd_opt(year, month, day).expect("valid date")
     }
 
+    #[test]
+    fn stock_state_cache_resets_before_reusing_compact_keys_on_another_date() {
+        let dates = [d(2025, 1, 2), d(2025, 1, 3)];
+        let symbol = "300001.SZ";
+        let market = |date: NaiveDate, close: f64| DailyMarketSnapshot {
+            date,
+            symbol: symbol.to_string(),
+            timestamp: None,
+            day_open: close,
+            open: close,
+            high: close,
+            low: close,
+            close,
+            last_price: close,
+            bid1: close,
+            ask1: close,
+            prev_close: close,
+            volume: 1_000_000,
+            minute_volume: 10_000,
+            bid1_volume: 10_000,
+            ask1_volume: 10_000,
+            trading_phase: Some("continuous".to_string()),
+            paused: false,
+            upper_limit: close * 1.1,
+            lower_limit: close * 0.9,
+            price_tick: 0.01,
+        };
+        let factor = |date: NaiveDate| DailyFactorSnapshot {
+            date,
+            symbol: symbol.to_string(),
+            market_cap_bn: 10.0,
+            free_float_cap_bn: 9.0,
+            pe_ttm: 12.0,
+            turnover_ratio: Some(1.0),
+            effective_turnover_ratio: Some(1.0),
+            extra_factors: BTreeMap::from([("adjustment_factor_backward1".into(), 1.0)]),
+        };
+        let candidate = |date: NaiveDate| CandidateEligibility {
+            date,
+            symbol: symbol.to_string(),
+            is_st: false,
+            is_star_st: false,
+            is_new_listing: false,
+            is_paused: false,
+            allow_buy: true,
+            allow_sell: true,
+            is_kcb: false,
+            is_one_yuan: false,
+            risk_level_code: None,
+        };
+        let data = DataSet::from_components(
+            vec![Instrument {
+                symbol: symbol.to_string(),
+                name: symbol.to_string(),
+                board: "SZ".to_string(),
+                round_lot: 100,
+                listed_at: Some(d(2020, 1, 1)),
+                delisted_at: None,
+                status: "active".to_string(),
+            }],
+            vec![market(dates[0], 10.0), market(dates[1], 11.0)],
+            dates.into_iter().map(factor).collect(),
+            dates.into_iter().map(candidate).collect(),
+            dates
+                .into_iter()
+                .map(|date| BenchmarkSnapshot {
+                    date,
+                    benchmark: "000852.SH".to_string(),
+                    open: 1_000.0,
+                    close: 1_000.0,
+                    prev_close: 1_000.0,
+                    volume: 1_000_000,
+                })
+                .collect(),
+        )
+        .expect("cache test dataset");
+        let portfolio = PortfolioState::new(100_000.0);
+        let subscriptions = BTreeSet::new();
+        let context = |date: NaiveDate, decision_index: usize| StrategyContext {
+            execution_date: date,
+            decision_date: date,
+            decision_index,
+            data: &data,
+            portfolio: &portfolio,
+            futures_account: None,
+            open_orders: &[],
+            dynamic_universe: None,
+            subscriptions: &subscriptions,
+            process_events: &[],
+            active_process_event: None,
+            active_datetime: None,
+            order_events: &[],
+            fills: &[],
+        };
+        let strategy = PlatformExprStrategy::new(PlatformExprStrategyConfig::microcap_rotation());
+        let first_context = context(dates[0], 0);
+        let first = strategy
+            .stock_state(&first_context, dates[0], symbol)
+            .expect("first state");
+        let first_again = strategy
+            .stock_state(&first_context, dates[0], symbol)
+            .expect("cached first state");
+        assert!(Arc::ptr_eq(&first, &first_again));
+        assert_eq!(first.close, 10.0);
+
+        let second_context = context(dates[1], 1);
+        let second = strategy
+            .stock_state(&second_context, dates[1], symbol)
+            .expect("second state");
+        assert!(!Arc::ptr_eq(&first, &second));
+        assert_eq!(second.close, 11.0);
+        assert_eq!(*strategy.stock_state_cache_date.borrow(), Some(dates[1]));
+        assert_eq!(strategy.stock_state_cache.borrow().len(), 1);
+    }
+
     #[test]
     fn dated_position_exposure_uses_the_latest_effective_point() {
         let schedule = BTreeMap::from([(d(2026, 8, 14), 0.6451), (d(2026, 8, 20), 0.3225)]);