diff --git a/rdagent/scenarios/qlib/experiment/factor_data_template/generate.py b/rdagent/scenarios/qlib/experiment/factor_data_template/generate.py
index f05aee5b02..9bf71810e3 100755
--- a/rdagent/scenarios/qlib/experiment/factor_data_template/generate.py
+++ b/rdagent/scenarios/qlib/experiment/factor_data_template/generate.py
@@ -12,16 +12,14 @@
 
 
 fields = ["$open", "$close", "$high", "$low", "$volume", "$factor"]
-data = (
-    (
-        D.features(instruments, fields, start_time="2018-01-01", end_time="2019-12-31", freq="day")
-        .swaplevel()
-        .sort_index()
-    )
-    .swaplevel()
-    .loc[data.reset_index()["instrument"].unique()[:100]]
-    .swaplevel()
+# Debug slice: pick instruments that actually trade in the debug window.
+# (Taking the first 100 of the full-history panel breaks on universes with
+# delisted securities: names dead before 2018 are absent from this window.)
+data_debug = (
+    D.features(instruments, fields, start_time="2018-01-01", end_time="2019-12-31", freq="day")
     .sort_index()
 )
+keep = data_debug.index.get_level_values("instrument").unique()[:100]
+data_debug = data_debug.loc[keep].swaplevel().sort_index()
 
-data.to_hdf("./daily_pv_debug.h5", key="data")
+data_debug.to_hdf("./daily_pv_debug.h5", key="data")