diff --git a/core.lua b/core.lua
index 3fbf1b6..ff5ed74 100644
--- a/core.lua
+++ b/core.lua
@@ -1,5 +1,5 @@
 Aux = {
-    version = '2.7.4',
+    version = '2.7.5',
     blizzard_ui_shown = false,
 	orig = {},
 }
diff --git a/history.lua b/history.lua
index 287abf9..dbef0b3 100644
--- a/history.lua
+++ b/history.lua
@@ -88,7 +88,7 @@ function public.value(item_key)
 			local weighted_values = {}
 			local total_weight = 0
 			for _, data_point in item_record.data_points do
-				local weight = 0.99^Aux.round((data_point.time - item_record.data_points[1].time) / (60*60*24))
+				local weight = 0.99^Aux.round((item_record.data_points[1].time - data_point.time) / (60*60*24))
 				total_weight = total_weight + weight
 				tinsert(weighted_values, {value = data_point.market_value, weight = weight})
 			end