diff --git a/crates/fidc-core/src/engine.rs b/crates/fidc-core/src/engine.rs
index c56a435..d7111c5 100644
--- a/crates/fidc-core/src/engine.rs
+++ b/crates/fidc-core/src/engine.rs
@@ -560,6 +560,9 @@ where
             if self.execution_quote_request_cache.contains(&request_key) {
                 return false;
             }
+            if start_time.is_some() && end_time.is_none() {
+                return true;
+            }
             !has_execution_quote_in_window(&self.data, execution_date, symbol, start_time, end_time)
         });
         if symbols.is_empty() {