diff --git a/crates/fidc-core/src/data.rs b/crates/fidc-core/src/data.rs
index 1ccf1cd..b3f815d 100644
--- a/crates/fidc-core/src/data.rs
+++ b/crates/fidc-core/src/data.rs
@@ -2456,6 +2456,13 @@ impl DataSet {
             .unwrap_or_default()
     }
 
+    pub fn market_snapshot_rows_on(&self, date: NaiveDate) -> &[DailyMarketSnapshot] {
+        self.market_by_date
+            .get(&date)
+            .map(Vec::as_slice)
+            .unwrap_or(&[])
+    }
+
     pub fn candidate_snapshots_on(&self, date: NaiveDate) -> Vec<&CandidateEligibility> {
         self.candidate_by_date
             .get(&date)
@@ -2463,6 +2470,13 @@ impl DataSet {
             .unwrap_or_default()
     }
 
+    pub fn candidate_snapshot_rows_on(&self, date: NaiveDate) -> &[CandidateEligibility] {
+        self.candidate_by_date
+            .get(&date)
+            .map(Vec::as_slice)
+            .unwrap_or(&[])
+    }
+
     pub fn bundle_on(&self, date: NaiveDate) -> Result<DailySnapshotBundle, DataSetError> {
         let benchmark = self
             .benchmark(date)
diff --git a/crates/fidc-core/src/engine.rs b/crates/fidc-core/src/engine.rs
index be7bf87..189275a 100644
--- a/crates/fidc-core/src/engine.rs
+++ b/crates/fidc-core/src/engine.rs
@@ -1778,11 +1778,11 @@ where
             .filter(|date| self.config.end_date.map(|end| *date <= end).unwrap_or(true))
             .collect::<Vec<_>>();
         let has_decision_inputs = |date: NaiveDate| {
-            !self.data.factor_snapshots_on(date).is_empty()
-                && !self.data.candidate_snapshots_on(date).is_empty()
+            !self.data.factor_snapshot_rows_on(date).is_empty()
+                && !self.data.candidate_snapshot_rows_on(date).is_empty()
         };
         let has_execution_market =
-            |date: NaiveDate| !self.data.market_snapshots_on(date).is_empty();
+            |date: NaiveDate| !self.data.market_snapshot_rows_on(date).is_empty();
         let mut execution_dates = Vec::new();
         let mut decision_slots = Vec::new();
         for (calendar_idx, execution_date) in calendar_dates.iter().copied().enumerate() {
diff --git a/crates/fidc-core/src/platform_expr_strategy.rs b/crates/fidc-core/src/platform_expr_strategy.rs
index f1b6aa2..5624451 100644
--- a/crates/fidc-core/src/platform_expr_strategy.rs
+++ b/crates/fidc-core/src/platform_expr_strategy.rs
@@ -3678,8 +3678,8 @@ impl PlatformExprStrategy {
             is_month_end,
             available_factor_names: if self.stock_extra_factors_required {
                 ctx.data
-                    .factor_snapshots_on(date)
-                    .into_iter()
+                    .factor_snapshot_rows_on(date)
+                    .iter()
                     .flat_map(|row| row.extra_factors.keys().map(|key| key.to_string()))
                     .collect()
             } else {
@@ -7797,7 +7797,7 @@ impl PlatformExprStrategy {
             return;
         };
         let mut map = Map::new();
-        for snapshot in ctx.data.market_snapshots_on(date) {
+        for snapshot in ctx.data.market_snapshot_rows_on(date) {
             if let Some(value) = Self::market_scope_value(snapshot, field) {
                 map.insert(snapshot.symbol.clone().into(), Dynamic::from(value));
             }
diff --git a/crates/fidc-core/src/strategy.rs b/crates/fidc-core/src/strategy.rs
index 8c8aed1..3470740 100644
--- a/crates/fidc-core/src/strategy.rs
+++ b/crates/fidc-core/src/strategy.rs
@@ -2541,7 +2541,7 @@ impl OmniMicroCapStrategy {
         date: NaiveDate,
     ) -> Vec<FidcRiskDecisionAudit> {
         let mut decisions = Vec::new();
-        for factor in ctx.data.factor_snapshots_on(date) {
+        for factor in ctx.data.factor_snapshot_rows_on(date) {
             if ctx.has_dynamic_universe() && !ctx.dynamic_universe_contains(&factor.symbol) {
                 continue;
             }
diff --git a/crates/fidc-core/src/universe.rs b/crates/fidc-core/src/universe.rs
index c92b556..8c6d959 100644
--- a/crates/fidc-core/src/universe.rs
+++ b/crates/fidc-core/src/universe.rs
@@ -80,7 +80,7 @@ impl SelectionContext<'_> {
             }
         };
         let mut decisions = Vec::new();
-        for factor in self.data.factor_snapshots_on(self.decision_date) {
+        for factor in self.data.factor_snapshot_rows_on(self.decision_date) {
             if self
                 .dynamic_universe
                 .is_some_and(|symbols| !symbols.is_empty() && !symbols.contains(&factor.symbol))
@@ -213,7 +213,7 @@ impl UniverseSelector for DynamicMarketCapBandSelector {
             risk_decisions: Vec::new(),
         };
 
-        diagnostics.factor_total = ctx.data.factor_snapshots_on(ctx.decision_date).len();
+        diagnostics.factor_total = ctx.data.factor_snapshot_rows_on(ctx.decision_date).len();
         diagnostics.risk_decisions = ctx.selection_risk_decisions();
         diagnostics.not_eligible_count = diagnostics.risk_decisions.len();
         diagnostics.paused_count = diagnostics