diff --git a/backend/internal/repository/usage_log_repo.go b/backend/internal/repository/usage_log_repo.go
index d30cc7dd..ff40e97d 100644
--- a/backend/internal/repository/usage_log_repo.go
+++ b/backend/internal/repository/usage_log_repo.go
@@ -1655,6 +1655,13 @@ func (r *usageLogRepository) GetBatchAPIKeyUsageStats(ctx context.Context, apiKe
 
 // GetUsageTrendWithFilters returns usage trend data with optional filters
 func (r *usageLogRepository) GetUsageTrendWithFilters(ctx context.Context, startTime, endTime time.Time, granularity string, userID, apiKeyID, accountID, groupID int64, model string, requestType *int16, stream *bool, billingType *int8) (results []TrendDataPoint, err error) {
+	if shouldUsePreaggregatedTrend(granularity, userID, apiKeyID, accountID, groupID, model, requestType, stream, billingType) {
+		aggregated, aggregatedErr := r.getUsageTrendFromAggregates(ctx, startTime, endTime, granularity)
+		if aggregatedErr == nil && len(aggregated) > 0 {
+			return aggregated, nil
+		}
+	}
+
 	dateFormat := safeDateFormat(granularity)
 
 	query := fmt.Sprintf(`
@@ -1719,6 +1726,78 @@ func (r *usageLogRepository) GetUsageTrendWithFilters(ctx context.Context, start
 	return results, nil
 }
 
+func shouldUsePreaggregatedTrend(granularity string, userID, apiKeyID, accountID, groupID int64, model string, requestType *int16, stream *bool, billingType *int8) bool {
+	if granularity != "day" && granularity != "hour" {
+		return false
+	}
+	return userID == 0 &&
+		apiKeyID == 0 &&
+		accountID == 0 &&
+		groupID == 0 &&
+		model == "" &&
+		requestType == nil &&
+		stream == nil &&
+		billingType == nil
+}
+
+func (r *usageLogRepository) getUsageTrendFromAggregates(ctx context.Context, startTime, endTime time.Time, granularity string) (results []TrendDataPoint, err error) {
+	dateFormat := safeDateFormat(granularity)
+	query := ""
+	args := []any{startTime, endTime}
+
+	switch granularity {
+	case "hour":
+		query = fmt.Sprintf(`
+			SELECT
+				TO_CHAR(bucket_start, '%s') as date,
+				total_requests as requests,
+				input_tokens,
+				output_tokens,
+				(cache_creation_tokens + cache_read_tokens) as cache_tokens,
+				(input_tokens + output_tokens + cache_creation_tokens + cache_read_tokens) as total_tokens,
+				total_cost as cost,
+				actual_cost
+			FROM usage_dashboard_hourly
+			WHERE bucket_start >= $1 AND bucket_start < $2
+			ORDER BY bucket_start ASC
+		`, dateFormat)
+	case "day":
+		query = fmt.Sprintf(`
+			SELECT
+				TO_CHAR(bucket_date::timestamp, '%s') as date,
+				total_requests as requests,
+				input_tokens,
+				output_tokens,
+				(cache_creation_tokens + cache_read_tokens) as cache_tokens,
+				(input_tokens + output_tokens + cache_creation_tokens + cache_read_tokens) as total_tokens,
+				total_cost as cost,
+				actual_cost
+			FROM usage_dashboard_daily
+			WHERE bucket_date >= $1::date AND bucket_date < $2::date
+			ORDER BY bucket_date ASC
+		`, dateFormat)
+	default:
+		return nil, nil
+	}
+
+	rows, err := r.sql.QueryContext(ctx, query, args...)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if closeErr := rows.Close(); closeErr != nil && err == nil {
+			err = closeErr
+			results = nil
+		}
+	}()
+
+	results, err = scanTrendRows(rows)
+	if err != nil {
+		return nil, err
+	}
+	return results, nil
+}
+
 // GetModelStatsWithFilters returns model statistics with optional filters
 func (r *usageLogRepository) GetModelStatsWithFilters(ctx context.Context, startTime, endTime time.Time, userID, apiKeyID, accountID, groupID int64, requestType *int16, stream *bool, billingType *int8) (results []ModelStat, err error) {
 	actualCostExpr := "COALESCE(SUM(actual_cost), 0) as actual_cost"
diff --git a/frontend/src/views/admin/DashboardView.vue b/frontend/src/views/admin/DashboardView.vue
index d4f1fbb0..ac5c44af 100644
--- a/frontend/src/views/admin/DashboardView.vue
+++ b/frontend/src/views/admin/DashboardView.vue
@@ -246,7 +246,10 @@
               {{ t('admin.dashboard.recentUsage') }} (Top 12)
             </h3>
             <div class="h-64">
-              <Line v-if="userTrendChartData" :data="userTrendChartData" :options="lineOptions" />
+              <div v-if="userTrendLoading" class="flex h-full items-center justify-center">
+                <LoadingSpinner size="md" />
+              </div>
+              <Line v-else-if="userTrendChartData" :data="userTrendChartData" :options="lineOptions" />
               <div
                 v-else
                 class="flex h-full items-center justify-center text-sm text-gray-500 dark:text-gray-400"
@@ -306,11 +309,13 @@ const appStore = useAppStore()
 const stats = ref<DashboardStats | null>(null)
 const loading = ref(false)
 const chartsLoading = ref(false)
+const userTrendLoading = ref(false)
 
 // Chart data
 const trendData = ref<TrendDataPoint[]>([])
 const modelStats = ref<ModelStat[]>([])
 const userTrend = ref<UserUsageTrendPoint[]>([])
+let chartLoadSeq = 0
 
 // Helper function to format date in local timezone
 const formatLocalDate = (date: Date): string => {
@@ -531,7 +536,9 @@ const loadDashboardStats = async () => {
 }
 
 const loadChartData = async () => {
+  const currentSeq = ++chartLoadSeq
   chartsLoading.value = true
+  userTrendLoading.value = true
   try {
     const params = {
       start_date: startDate.value,
@@ -539,20 +546,39 @@ const loadChartData = async () => {
       granularity: granularity.value
     }
 
-    const [trendResponse, modelResponse, userResponse] = await Promise.all([
+    const [trendResponse, modelResponse] = await Promise.all([
       adminAPI.dashboard.getUsageTrend(params),
-      adminAPI.dashboard.getModelStats({ start_date: startDate.value, end_date: endDate.value }),
-      adminAPI.dashboard.getUserUsageTrend({ ...params, limit: 12 })
+      adminAPI.dashboard.getModelStats({ start_date: startDate.value, end_date: endDate.value })
     ])
 
+    if (currentSeq !== chartLoadSeq) return
     trendData.value = trendResponse.trend || []
     modelStats.value = modelResponse.models || []
-    userTrend.value = userResponse.trend || []
   } catch (error) {
+    if (currentSeq !== chartLoadSeq) return
     console.error('Error loading chart data:', error)
   } finally {
+    if (currentSeq !== chartLoadSeq) return
     chartsLoading.value = false
   }
+
+  try {
+    const params = {
+      start_date: startDate.value,
+      end_date: endDate.value,
+      granularity: granularity.value,
+      limit: 12
+    }
+    const userResponse = await adminAPI.dashboard.getUserUsageTrend(params)
+    if (currentSeq !== chartLoadSeq) return
+    userTrend.value = userResponse.trend || []
+  } catch (error) {
+    if (currentSeq !== chartLoadSeq) return
+    console.error('Error loading user trend:', error)
+  } finally {
+    if (currentSeq !== chartLoadSeq) return
+    userTrendLoading.value = false
+  }
 }
 
 onMounted(() => {