diff --git a/dashboard/public/index.html b/dashboard/public/index.html
index 1d71ca6..d18a719 100644
--- a/dashboard/public/index.html
+++ b/dashboard/public/index.html
@@ -203,14 +203,24 @@
             updateUrlParams();
         }
 
-        async function loadStatistics() {
+        async function loadStatistics(forceReload = false) {
             const days = parseInt(document.getElementById('statisticsPeriod')?.value || '7');
-            // Lade die Graphen (ohne fetchData aufzurufen, um Zucken zu vermeiden)
-            await Promise.all([
-                loadMovingAverage(days),
-                loadVolumeChanges(days),
-                loadStockTrends(days)
-            ]);
+            
+            // Beim ersten Laden oder bei expliziter Anforderung: Daten laden
+            if (forceReload || !store.trades || store.trades.length === 0) {
+                await fetchData(true); // skipCharts = true, damit Graphen nicht doppelt geladen werden
+            }
+            
+            // Lade die Graphen
+            try {
+                await Promise.all([
+                    loadMovingAverage(days),
+                    loadVolumeChanges(days),
+                    loadStockTrends(days)
+                ]);
+            } catch (err) {
+                console.error('Error loading statistics:', err);
+            }
             updateUrlParams();
         }
 
@@ -225,7 +235,12 @@
                     return;
                 }
                 
-                const ctx = document.getElementById('movingAverageChart').getContext('2d');
+                const canvas = document.getElementById('movingAverageChart');
+                if (!canvas) {
+                    console.error('Canvas element movingAverageChart not found');
+                    return;
+                }
+                const ctx = canvas.getContext('2d');
                 if (charts.movingAverage) charts.movingAverage.destroy();
                 
                 const dateIdx = columns.findIndex(c => c.name === 'date' || c.name === 'timestamp');
@@ -340,7 +355,12 @@
                     return;
                 }
                 
-                const ctx = document.getElementById('volumeChangesChart').getContext('2d');
+                const canvas = document.getElementById('volumeChangesChart');
+                if (!canvas) {
+                    console.error('Canvas element volumeChangesChart not found');
+                    return;
+                }
+                const ctx = canvas.getContext('2d');
                 if (charts.volumeChanges) charts.volumeChanges.destroy();
                 
                 const exchangeIdx = columns.findIndex(c => c.name === 'exchange');
@@ -425,7 +445,12 @@
                     return;
                 }
                 
-                const ctx = document.getElementById('stockTrendsChart').getContext('2d');
+                const canvas = document.getElementById('stockTrendsChart');
+                if (!canvas) {
+                    console.error('Canvas element stockTrendsChart not found');
+                    return;
+                }
+                const ctx = canvas.getContext('2d');
                 const tableContainer = document.getElementById('stockTrendsTable');
                 
                 if (charts.stockTrends) charts.stockTrends.destroy();
@@ -747,7 +772,8 @@
                 fetchData(true); // skipCharts = true
             }, 30000);
             
-            setTimeout(() => loadStatistics(), 1000);
+            // Lade Statistiken nach kurzer Verzögerung (forceReload = true beim ersten Laden)
+            setTimeout(() => loadStatistics(true), 1000);
         };
     </script>
 </body>
diff --git a/src/analytics/worker.py b/src/analytics/worker.py
index 907c8c9..40790ca 100644
--- a/src/analytics/worker.py
+++ b/src/analytics/worker.py
@@ -26,6 +26,31 @@ class AnalyticsWorker:
         self.last_processed_timestamp = None
         self.db_url = DB_URL
     
+    def query_questdb(self, query: str, timeout: int = 30) -> Optional[Dict]:
+        """Zentrale QuestDB-Abfrage-Funktion"""
+        try:
+            response = requests.get(f"{self.db_url}/exec", params={'query': query}, auth=DB_AUTH, timeout=timeout)
+            if response.status_code == 200:
+                data = response.json()
+                # Prüfe auf Fehler in der JSON-Antwort (z.B. "table does not exist")
+                if isinstance(data, dict) and 'error' in data:
+                    # Für "table does not exist" Fehler, geben wir None zurück (wird als leere Tabelle behandelt)
+                    if 'does not exist' in str(data.get('error', '')):
+                        return None
+                    logger.debug(f"QuestDB query error: {data.get('error')}")
+                    return None
+                return data
+            else:
+                # Bei 400/404 Fehlern (z.B. Tabelle existiert nicht), geben wir None zurück
+                if response.status_code in [400, 404]:
+                    logger.debug(f"QuestDB query failed (table may not exist): {response.status_code}")
+                    return None
+                logger.error(f"QuestDB query failed: {response.status_code} - {response.text}")
+                return None
+        except Exception as e:
+            logger.debug(f"Error querying QuestDB: {e}")
+            return None
+    
     def wait_for_questdb(self, max_retries: int = 30, retry_delay: int = 2):
         """Wartet bis QuestDB verfügbar ist"""
         logger.info("Waiting for QuestDB to be available...")
@@ -545,6 +570,31 @@ class AnalyticsWorker:
         
         logger.info(f"Completed processing for {date}")
     
+    def get_existing_dates(self, table_name: str) -> set:
+        """Holt alle bereits berechneten Daten aus einer Analytics-Tabelle"""
+        query = f"select distinct date_trunc('day', timestamp) as date from {table_name}"
+        data = self.query_questdb(query)
+        if not data:
+            # Tabelle existiert noch nicht - das ist OK beim ersten Start
+            return set()
+        
+        # Prüfe auf Fehler in der Antwort (z.B. "table does not exist")
+        if isinstance(data, dict) and 'error' in data:
+            logger.debug(f"Table {table_name} does not exist yet: {data.get('error')}")
+            return set()
+        
+        if not data.get('dataset'):
+            return set()
+        
+        dates = set()
+        for row in data['dataset']:
+            if row and row[0]:
+                if isinstance(row[0], str):
+                    dates.add(datetime.datetime.fromisoformat(row[0].replace('Z', '+00:00')).date())
+                elif isinstance(row[0], (int, float)):
+                    dates.add(datetime.datetime.fromtimestamp(row[0] / 1000000, tz=datetime.timezone.utc).date())
+        return dates
+    
     def get_missing_dates(self) -> List[datetime.date]:
         """Ermittelt fehlende Tage, die noch berechnet werden müssen"""
         # Hole das Datum des ersten Trades
@@ -561,7 +611,7 @@ class AnalyticsWorker:
             first_date = datetime.datetime.fromtimestamp(first_date_value / 1000000, tz=datetime.timezone.utc).date()
         
         # Hole bereits berechnete Daten
-        existing_dates = self.get_existing_dates('analytics_daily_summary')
+        existing_dates = self.get_existing_dates('analytics_custom')
         
         # Generiere alle Tage vom ersten Trade bis gestern
         yesterday = datetime.date.today() - datetime.timedelta(days=1)