diff --git a/crates/fidc-core/src/data.rs b/crates/fidc-core/src/data.rs
index 25c7bda..153e97a 100644
--- a/crates/fidc-core/src/data.rs
+++ b/crates/fidc-core/src/data.rs
@@ -4323,7 +4323,7 @@ fn build_fundamental_universe_for_date(
             free_float_cap_bn: decision_free_float_cap_bn(factor),
         });
     }
-    rows.sort_by(|left, right| {
+    rows.sort_unstable_by(|left, right| {
         left.market_cap_bn
             .partial_cmp(&right.market_cap_bn)
             .unwrap_or(std::cmp::Ordering::Equal)
@@ -4406,7 +4406,7 @@ fn build_eligible_universe_for_date_from_factors(
             free_float_cap_bn,
         });
     }
-    rows.sort_by(|left, right| {
+    rows.sort_unstable_by(|left, right| {
         left.market_cap_bn
             .partial_cmp(&right.market_cap_bn)
             .unwrap_or(std::cmp::Ordering::Equal)
diff --git a/crates/fidc-core/src/platform_expr_strategy.rs b/crates/fidc-core/src/platform_expr_strategy.rs
index 04556c3..e55f257 100644
--- a/crates/fidc-core/src/platform_expr_strategy.rs
+++ b/crates/fidc-core/src/platform_expr_strategy.rs
@@ -8976,7 +8976,7 @@ impl PlatformExprStrategy {
                 free_float_cap_bn,
             });
         }
-        rows.sort_by(|left, right| {
+        rows.sort_unstable_by(|left, right| {
             left.market_cap_bn
                 .partial_cmp(&right.market_cap_bn)
                 .unwrap_or(std::cmp::Ordering::Equal)
@@ -9562,7 +9562,7 @@ impl PlatformExprStrategy {
             candidates.push((candidate, stock, rank_value));
         }
         if !self.rank_reuses_market_cap_order() {
-            candidates.sort_by(|lhs, rhs| {
+            candidates.sort_unstable_by(|lhs, rhs| {
                 let lhs_value = lhs.2;
                 let rhs_value = rhs.2;
                 let ordering = if self.config.rank_desc {
@@ -10204,7 +10204,7 @@ impl PlatformExprStrategy {
             }
             candidates.push((candidate.symbol.clone(), rank_value, stock));
         }
-        candidates.sort_by(|lhs, rhs| {
+        candidates.sort_unstable_by(|lhs, rhs| {
             let ordering = if self.config.rank_desc {
                 rhs.1
                     .partial_cmp(&lhs.1)