diff --git a/nummi/main/migrations/0018_snapshot_diff_alter_snapshot_account.py b/nummi/main/migrations/0018_snapshot_diff_alter_snapshot_account.py
new file mode 100644
index 0000000..2f40d1e
--- /dev/null
+++ b/nummi/main/migrations/0018_snapshot_diff_alter_snapshot_account.py
@@ -0,0 +1,34 @@
+# Generated by Django 4.1.4 on 2022-12-29 20:56
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("main", "0017_alter_transaction_account"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="snapshot",
+            name="diff",
+            field=models.DecimalField(
+                decimal_places=2,
+                default=0,
+                editable=False,
+                max_digits=12,
+                verbose_name="Différence",
+            ),
+        ),
+        migrations.AlterField(
+            model_name="snapshot",
+            name="account",
+            field=models.ForeignKey(
+                on_delete=django.db.models.deletion.CASCADE,
+                to="main.account",
+                verbose_name="Account",
+            ),
+        ),
+    ]
diff --git a/nummi/main/migrations/0019_snapshot_sum.py b/nummi/main/migrations/0019_snapshot_sum.py
new file mode 100644
index 0000000..6a6cf87
--- /dev/null
+++ b/nummi/main/migrations/0019_snapshot_sum.py
@@ -0,0 +1,24 @@
+# Generated by Django 4.1.4 on 2022-12-29 20:57
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("main", "0018_snapshot_diff_alter_snapshot_account"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="snapshot",
+            name="sum",
+            field=models.DecimalField(
+                decimal_places=2,
+                default=0,
+                editable=False,
+                max_digits=12,
+                verbose_name="Transaction difference",
+            ),
+        ),
+    ]
diff --git a/nummi/main/models.py b/nummi/main/models.py
index 3694261..82d972b 100644
--- a/nummi/main/models.py
+++ b/nummi/main/models.py
@@ -4,7 +4,7 @@ import uuid
 
 from django.conf import settings
 from django.core.validators import FileExtensionValidator
-from django.db import models
+from django.db import models, transaction
 from django.forms import ModelForm
 from django.urls import reverse
 from django.utils.translation import gettext as _
@@ -64,9 +64,7 @@ class Account(CustomModel):
 class AccountModel(CustomModel):
     account = models.ForeignKey(
         Account,
-        on_delete=models.SET_NULL,
-        blank=True,
-        null=True,
+        on_delete=models.CASCADE,
         verbose_name=_("Account"),
     )
 
@@ -117,6 +115,20 @@ class Snapshot(AccountModel):
     start_value = models.DecimalField(
         max_digits=12, decimal_places=2, default=0, verbose_name=_("Start value")
     )
+    diff = models.DecimalField(
+        max_digits=12,
+        decimal_places=2,
+        default=0,
+        verbose_name=_("Difference"),
+        editable=False,
+    )
+    sum = models.DecimalField(
+        max_digits=12,
+        decimal_places=2,
+        default=0,
+        verbose_name=_("Transaction difference"),
+        editable=False,
+    )
     file = models.FileField(
         upload_to=snapshot_path,
         validators=[FileExtensionValidator(["pdf"])],
@@ -135,8 +147,18 @@ class Snapshot(AccountModel):
             if _prever.file and _prever.file != self.file:
                 pathlib.Path(_prever.file.path).unlink(missing_ok=True)
 
+        with transaction.atomic():
+            for trans in self.transaction_set.all():
+                trans.save()
+
+        self.diff = self.value - self.start_value
+        self.sum = self.transaction_set.aggregate(sum=models.Sum("value")).get("sum", 0)
         super().save(*args, **kwargs)
 
+    def update_sum(self):
+        self.sum = self.transaction_set.aggregate(sum=models.Sum("value")).get("sum", 0)
+        super().save()
+
     def delete(self, *args, only_super=False, **kwargs):
         if self.file:
             self.file.delete()
@@ -147,24 +169,6 @@ class Snapshot(AccountModel):
     def get_delete_url(self):
         return reverse("del_snapshot", kwargs={"pk": self.pk})
 
-    @property
-    def pos(self):
-        return (
-            self.transactions.filter(value__gt=0).aggregate(sum=models.Sum("value"))[
-                "sum"
-            ]
-            or 0
-        )
-
-    @property
-    def neg(self):
-        return (
-            self.transactions.filter(value__lt=0).aggregate(sum=models.Sum("value"))[
-                "sum"
-            ]
-            or 0
-        )
-
     class Meta:
         ordering = ["-date"]
         verbose_name = _("Statement")
@@ -209,6 +213,7 @@ class Transaction(CustomModel):
 
     def save(self, *args, **kwargs):
         self.account = self.snapshot.account
+        self.snapshot.update_sum()
         super().save(*args, **kwargs)
 
     def __str__(self):
diff --git a/nummi/main/templates/main/index.html b/nummi/main/templates/main/index.html
index c4e5c84..499a59f 100644
--- a/nummi/main/templates/main/index.html
+++ b/nummi/main/templates/main/index.html
@@ -66,25 +66,19 @@
                         <a href="{% url 'snapshot' snap.id %}">{{ snap.date|date:"Y-m-d" }}</a>
                     </span>
                     <span class="account text center">
-                        {% if trans.account %}
-                            <i class="fa fa-{{ trans.account.icon }}"></i>
-                            <a href="{% url 'account' trans.account.id %}">{{ trans.account }}</a>
-                        {% else %}
-                            –
-                        {% endif %}
+                            <i class="fa fa-{{ snap.account.icon }}"></i>
+                            <a href="{% url 'account' snap.account.id %}">{{ snap.account }}</a>
                     </span>
                     <span class="value num right">{{ snap.value|value }}</span>
                     <span class="diff num right">{{ snap.diff|pmvalue }}</span>
                     {% with sum=snap.sum %}
                         <span class="sum num right">{{ sum|pmvalue }}</span>
                         <span class="valid center">
-                            {% if snap.previous is not None %}
                                 {% if sum == snap.diff %}
                                     <i class="fa fa-check green"></i>
                                 {% else %}
                                     <i class="fa fa-xmark red"></i>
                                 {% endif %}
-                            {% endif %}
                         </span>
                     {% endwith %}
                 </div>