diff --git a/nullptr/models/marketplace.py b/nullptr/models/marketplace.py
index 88dbdc7..6bf916a 100644
--- a/nullptr/models/marketplace.py
+++ b/nullptr/models/marketplace.py
@@ -8,18 +8,26 @@ from typing import List, Tuple
 
 SUPPLY = ['SCARCE','LIMITED','MODERATE','HIGH','ABUNDANT']
 ACTIVITY =['RESTRICTED','WEAK','GROWING','STRONG']
+
 class MarketEntry:
-  buy: int
-  sell: int
-  volume: int
-  supply: int
-  activity: int
-  history: List[Tuple[int, int, int, int, int, int]] = []
+  def __init__(self):
+    self.buy = 0
+    self.sell = 0
+    self.volume = 0
+    self.supply = 0
+    self.activity = 0
+    self.history = []
   
+  def upg(self):
+    if not hasattr(self, 'history'):
+      self.history = []
+      
   def f(self, detail=1):
+    self.upg()
     return f'b: {self.buy} s:{self.sell} hist: {len(self.history)}'
     
   def add(self, buy, sell, volume, supply, activity):
+    self.upg()
     self.buy = buy
     self.sell = sell
     self.volume = volume