diff --git a/zipline/finance/performance.py b/zipline/finance/performance.py
index b68eb17d..3b2c1cdd 100644
--- a/zipline/finance/performance.py
+++ b/zipline/finance/performance.py
@@ -215,7 +215,7 @@ class PerformanceTracker(object):
 
                     new_snapshot.append(event)
 
-            if len(new_snapshot) > 0:
+            if new_snapshot:
                 yield date, new_snapshot
 
     def get_portfolio(self):