diff --git a/main.py b/main.py
index f4b397a..a0474d4 100644
--- a/main.py
+++ b/main.py
@@ -70,7 +70,8 @@ async def portfolio(ctx):
 
     # TODO: Raises ZeroDivisionError if user has no stocks
     total_delta = 100 * (
-        (current_portfolio_total_value / yesterday_portfolio_total_value) - 1
+        (current_portfolio_total_value - yesterday_portfolio_total_value)
+        / yesterday_portfolio_value
     )
 
     data.append(