diff --git a/.gitignore b/.gitignore
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--- a/.gitignore
+++ b/.gitignore
@@ -23,6 +23,7 @@ svg-inkscape/
 
 # Von den Beispielprogrammen beim Lauf erzeugte Dateien
 Operations_Research_mit_Python_Version_04_Programme/output/
+Notebooks_04/output/
 produktionsmix.xlsx
 produktionsmix_ergebnis.xlsx
 
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diff --git a/Notebooks_04/output/trading_engine_backtest.png b/Notebooks_04/output/trading_engine_backtest.png
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