diff --git a/apps/client/src/app/pages/portfolio/activities/create-or-update-activity-dialog/create-or-update-activity-dialog.component.ts b/apps/client/src/app/pages/portfolio/activities/create-or-update-activity-dialog/create-or-update-activity-dialog.component.ts
index cb21c255d..03c1dda69 100644
--- a/apps/client/src/app/pages/portfolio/activities/create-or-update-activity-dialog/create-or-update-activity-dialog.component.ts
+++ b/apps/client/src/app/pages/portfolio/activities/create-or-update-activity-dialog/create-or-update-activity-dialog.component.ts
@@ -148,7 +148,42 @@ export class CreateOrUpdateActivityDialog implements OnDestroy {
       ],
       updateAccountBalance: [false]
     });
-
+    this.activityForm.get('quantity').valueChanges.subscribe(async () => {
+      const activity = { quantity: this.activityForm.get('quantity').value };
+      try {
+        const ignoredFields = [
+          'accountId',
+          'assetClass',
+          'assetSubClass',
+          'comment',
+          'currency',
+          'customCurrency',
+          'dataSource',
+          'date',
+          'fee',
+          'symbol',
+          'tags',
+          'type',
+          'unitPrice',
+          'updateAccountBalance'
+        ];
+        if (this.mode === 'create') {
+          await validateObjectForForm({
+            classDto: CreateOrderDto,
+            form: this.activityForm,
+            ignoreFields: ignoredFields,
+            object: activity
+          });
+        } else {
+          await validateObjectForForm({
+            classDto: UpdateOrderDto,
+            form: this.activityForm,
+            ignoreFields: ignoredFields,
+            object: activity
+          });
+        }
+      } catch (error) {}
+    });
     this.activityForm.valueChanges
       .pipe(
         // Slightly delay until the more specific form control value changes have
diff --git a/apps/client/src/app/pages/portfolio/activities/create-or-update-activity-dialog/create-or-update-activity-dialog.html b/apps/client/src/app/pages/portfolio/activities/create-or-update-activity-dialog/create-or-update-activity-dialog.html
index dba624064..7795688c0 100644
--- a/apps/client/src/app/pages/portfolio/activities/create-or-update-activity-dialog/create-or-update-activity-dialog.html
+++ b/apps/client/src/app/pages/portfolio/activities/create-or-update-activity-dialog/create-or-update-activity-dialog.html
@@ -186,7 +186,7 @@
     >
       <mat-form-field appearance="outline" class="w-100">
         <mat-label i18n>Quantity</mat-label>
-        <input formControlName="quantity" matInput type="number" [min]="0" />
+        <input formControlName="quantity" matInput type="number" />
       </mat-form-field>
     </div>
     <div