diff --git a/crates/fidc-core/src/broker.rs b/crates/fidc-core/src/broker.rs
index 373a77f..fcd2f26 100644
--- a/crates/fidc-core/src/broker.rs
+++ b/crates/fidc-core/src/broker.rs
@@ -5689,7 +5689,7 @@ mod tests {
     use crate::instrument::Instrument;
     use crate::portfolio::PortfolioState;
     use crate::rules::ChinaEquityRuleHooks;
-    use crate::strategy::AlgoOrderStyle;
+    use crate::strategy::{AlgoOrderStyle, OrderIntent, StrategyDecision};
 
     fn limit_test_snapshot() -> DailyMarketSnapshot {
         let date = chrono::NaiveDate::from_ymd_opt(2025, 1, 2).expect("valid date");
@@ -5776,6 +5776,44 @@ mod tests {
         }
     }
 
+    fn dated_limit_test_snapshot(date: chrono::NaiveDate) -> DailyMarketSnapshot {
+        let mut snapshot = limit_test_snapshot();
+        snapshot.date = date;
+        snapshot.timestamp = Some(format!("{date} 09:31:00"));
+        snapshot
+    }
+
+    fn dated_limit_test_candidate(
+        date: chrono::NaiveDate,
+        is_st: bool,
+        is_paused: bool,
+        allow_buy: bool,
+        allow_sell: bool,
+    ) -> CandidateEligibility {
+        let mut candidate = limit_test_candidate(allow_buy, allow_sell);
+        candidate.date = date;
+        candidate.is_st = is_st;
+        candidate.is_paused = is_paused;
+        candidate
+    }
+
+    fn dated_limit_test_benchmark(date: chrono::NaiveDate) -> BenchmarkSnapshot {
+        let mut benchmark = limit_test_benchmark();
+        benchmark.date = date;
+        benchmark
+    }
+
+    fn next_open_buy_decision() -> StrategyDecision {
+        StrategyDecision {
+            order_intents: vec![OrderIntent::Shares {
+                symbol: "000001.SZ".to_string(),
+                quantity: 100,
+                reason: "signal_day_buy".to_string(),
+            }],
+            ..StrategyDecision::default()
+        }
+    }
+
     #[test]
     fn minute_last_without_volume_or_liquidity_limit_does_not_cap_quote_quantity() {
         let broker = BrokerSimulator::new(ChinaAShareCostModel::default(), ChinaEquityRuleHooks)
@@ -5814,6 +5852,107 @@ mod tests {
         assert!(broker.quote_quantity_limited(MatchingType::MinuteBestCounterparty));
     }
 
+    #[test]
+    fn next_open_buy_risk_uses_execution_date_not_signal_date() {
+        let signal_date = chrono::NaiveDate::from_ymd_opt(2025, 1, 2).expect("valid date");
+        let execution_date = chrono::NaiveDate::from_ymd_opt(2025, 1, 3).expect("valid date");
+        let broker = BrokerSimulator::new(ChinaAShareCostModel::default(), ChinaEquityRuleHooks)
+            .with_volume_limit(false)
+            .with_liquidity_limit(false);
+        let data = DataSet::from_components_with_actions_and_quotes(
+            vec![limit_test_instrument()],
+            vec![
+                dated_limit_test_snapshot(signal_date),
+                dated_limit_test_snapshot(execution_date),
+            ],
+            Vec::new(),
+            vec![
+                dated_limit_test_candidate(signal_date, true, true, false, false),
+                dated_limit_test_candidate(execution_date, false, false, true, true),
+            ],
+            vec![
+                dated_limit_test_benchmark(signal_date),
+                dated_limit_test_benchmark(execution_date),
+            ],
+            Vec::new(),
+            Vec::new(),
+        )
+        .expect("valid dataset");
+        let mut portfolio = PortfolioState::new(20_000.0);
+
+        let report = broker
+            .execute(
+                execution_date,
+                &mut portfolio,
+                &data,
+                &next_open_buy_decision(),
+            )
+            .expect("execute next open buy");
+
+        assert_eq!(report.fill_events.len(), 1);
+        assert_eq!(report.fill_events[0].date, execution_date);
+        assert_eq!(report.fill_events[0].quantity, 100);
+        assert_eq!(
+            portfolio
+                .position("000001.SZ")
+                .map(|position| position.quantity),
+            Some(100)
+        );
+    }
+
+    #[test]
+    fn next_open_buy_risk_rejects_execution_date_st_even_if_signal_date_was_clean() {
+        let signal_date = chrono::NaiveDate::from_ymd_opt(2025, 1, 2).expect("valid date");
+        let execution_date = chrono::NaiveDate::from_ymd_opt(2025, 1, 3).expect("valid date");
+        let broker = BrokerSimulator::new(ChinaAShareCostModel::default(), ChinaEquityRuleHooks)
+            .with_volume_limit(false)
+            .with_liquidity_limit(false);
+        let data = DataSet::from_components_with_actions_and_quotes(
+            vec![limit_test_instrument()],
+            vec![
+                dated_limit_test_snapshot(signal_date),
+                dated_limit_test_snapshot(execution_date),
+            ],
+            Vec::new(),
+            vec![
+                dated_limit_test_candidate(signal_date, false, false, true, true),
+                dated_limit_test_candidate(execution_date, true, false, true, true),
+            ],
+            vec![
+                dated_limit_test_benchmark(signal_date),
+                dated_limit_test_benchmark(execution_date),
+            ],
+            Vec::new(),
+            Vec::new(),
+        )
+        .expect("valid dataset");
+        let mut portfolio = PortfolioState::new(20_000.0);
+
+        let report = broker
+            .execute(
+                execution_date,
+                &mut portfolio,
+                &data,
+                &next_open_buy_decision(),
+            )
+            .expect("execute next open buy");
+
+        assert!(report.fill_events.is_empty());
+        assert!(portfolio.position("000001.SZ").is_none());
+        let rejected_order = report
+            .order_events
+            .iter()
+            .find(|event| event.side == OrderSide::Buy)
+            .expect("buy order event");
+        assert_eq!(rejected_order.date, execution_date);
+        assert_eq!(rejected_order.status, OrderStatus::Rejected);
+        assert!(
+            rejected_order.reason.contains("st"),
+            "{}",
+            rejected_order.reason
+        );
+    }
+
     #[test]
     fn current_bar_close_volume_limit_uses_daily_volume_when_minute_volume_missing() {
         let mut snapshot = limit_test_snapshot();