diff --git a/api/models.py b/api/models.py
index 35064586..6ceb9794 100644
--- a/api/models.py
+++ b/api/models.py
@@ -129,12 +129,12 @@ class LNPayment(models.Model):
     # involved parties
     sender = models.ForeignKey(User,
                                related_name="sender",
-                               on_delete=models.CASCADE,
+                               on_delete=models.SET_NULL,
                                null=True,
                                default=None)
     receiver = models.ForeignKey(User,
                                  related_name="receiver",
-                                 on_delete=models.CASCADE,
+                                 on_delete=models.SET_NULL,
                                  null=True,
                                  default=None)
 
diff --git a/frontend/src/components/TradeBox.js b/frontend/src/components/TradeBox.js
index 4a221c07..dbae9412 100644
--- a/frontend/src/components/TradeBox.js
+++ b/frontend/src/components/TradeBox.js
@@ -403,7 +403,7 @@ class TradeBox extends Component {
               <ListItemIcon>
                 <PercentIcon/>
               </ListItemIcon>
-                <ListItemText primary={t("Premium rank") +" "+this.props.data.premium_percentile*100+"%"}
+                <ListItemText primary={t("Premium rank") +" "+Number(this.props.data.premium_percentile*100).toPrecision(2)+"%"}
                   secondary={t("Among public {{currencyCode}} orders (higher is cheaper)",{ currencyCode: this.props.data.currencyCode })}/>
               </ListItem>
             <Divider/>