diff --git a/apps/api/src/modules/admin/infrastructure/repositories/admin-stats.queries.ts b/apps/api/src/modules/admin/infrastructure/repositories/admin-stats.queries.ts
index 2871e89..40566a9 100644
--- a/apps/api/src/modules/admin/infrastructure/repositories/admin-stats.queries.ts
+++ b/apps/api/src/modules/admin/infrastructure/repositories/admin-stats.queries.ts
@@ -43,67 +43,71 @@ export async function getDashboardStats(prisma: PrismaService): Promise<Dashboar
   };
 }
 
+// ---------------------------------------------------------------------------
+// Simple in-process cache for revenue stats (TTL = 60 seconds)
+// ---------------------------------------------------------------------------
+
+interface RevenueCacheEntry {
+  expiresAt: number;
+  data: RevenueStatsItem[];
+}
+
+const revenueStatsCache = new Map<string, RevenueCacheEntry>();
+
+function buildCacheKey(startDate: Date, endDate: Date, groupBy: string): string {
+  return `${startDate.toISOString()}|${endDate.toISOString()}|${groupBy}`;
+}
+
+// Raw row returned by Postgres for the aggregation query
+interface RevenueRawRow {
+  period: string;
+  total_revenue: bigint;
+  subscription_revenue: bigint;
+  listing_fee_revenue: bigint;
+  featured_listing_revenue: bigint;
+  transaction_count: bigint;
+}
+
 export async function getRevenueStats(
   prisma: PrismaService,
   startDate: Date,
   endDate: Date,
   groupBy: 'day' | 'month',
 ): Promise<RevenueStatsItem[]> {
-  const payments = await prisma.payment.findMany({
-    where: {
-      status: 'COMPLETED',
-      createdAt: { gte: startDate, lte: endDate },
-    },
-    select: {
-      type: true,
-      amountVND: true,
-      createdAt: true,
-    },
-    orderBy: { createdAt: 'asc' },
-  });
-
-  const grouped = new Map<string, {
-    totalRevenue: bigint;
-    subscriptionRevenue: bigint;
-    listingFeeRevenue: bigint;
-    featuredListingRevenue: bigint;
-    transactionCount: number;
-  }>();
-
-  for (const payment of payments) {
-    const period = groupBy === 'day'
-      ? payment.createdAt.toISOString().slice(0, 10)
-      : payment.createdAt.toISOString().slice(0, 7);
-
-    if (!grouped.has(period)) {
-      grouped.set(period, {
-        totalRevenue: 0n,
-        subscriptionRevenue: 0n,
-        listingFeeRevenue: 0n,
-        featuredListingRevenue: 0n,
-        transactionCount: 0,
-      });
-    }
-
-    const stats = grouped.get(period)!;
-    stats.totalRevenue += payment.amountVND;
-    stats.transactionCount++;
-
-    switch (payment.type) {
-      case 'SUBSCRIPTION':
-        stats.subscriptionRevenue += payment.amountVND;
-        break;
-      case 'LISTING_FEE':
-        stats.listingFeeRevenue += payment.amountVND;
-        break;
-      case 'FEATURED_LISTING':
-        stats.featuredListingRevenue += payment.amountVND;
-        break;
-    }
+  const cacheKey = buildCacheKey(startDate, endDate, groupBy);
+  const cached = revenueStatsCache.get(cacheKey);
+  if (cached && cached.expiresAt > Date.now()) {
+    return cached.data;
   }
 
-  return Array.from(grouped.entries()).map(([period, stats]) => ({
-    period,
-    ...stats,
+  const truncUnit = groupBy === 'day' ? 'day' : 'month';
+
+  const rows = await prisma.$queryRaw<RevenueRawRow[]>`
+    SELECT
+      TO_CHAR(DATE_TRUNC(${truncUnit}, "createdAt"), 'YYYY-MM-DD') AS period,
+      SUM("amountVND")                                               AS total_revenue,
+      SUM(CASE WHEN type = 'SUBSCRIPTION'      THEN "amountVND" ELSE 0 END) AS subscription_revenue,
+      SUM(CASE WHEN type = 'LISTING_FEE'       THEN "amountVND" ELSE 0 END) AS listing_fee_revenue,
+      SUM(CASE WHEN type = 'FEATURED_LISTING'  THEN "amountVND" ELSE 0 END) AS featured_listing_revenue,
+      COUNT(*)                                                       AS transaction_count
+    FROM "Payment"
+    WHERE status = 'COMPLETED'
+      AND "createdAt" >= ${startDate}
+      AND "createdAt" <= ${endDate}
+    GROUP BY DATE_TRUNC(${truncUnit}, "createdAt")
+    ORDER BY DATE_TRUNC(${truncUnit}, "createdAt") ASC
+  `;
+
+  const data: RevenueStatsItem[] = rows.map((row) => ({
+    period: row.period,
+    totalRevenue: BigInt(row.total_revenue),
+    subscriptionRevenue: BigInt(row.subscription_revenue),
+    listingFeeRevenue: BigInt(row.listing_fee_revenue),
+    featuredListingRevenue: BigInt(row.featured_listing_revenue),
+    transactionCount: Number(row.transaction_count),
   }));
+
+  revenueStatsCache.set(cacheKey, { expiresAt: Date.now() + 60_000, data });
+
+  return data;
 }
diff --git a/apps/api/src/modules/admin/presentation/dto/revenue-stats.dto.ts b/apps/api/src/modules/admin/presentation/dto/revenue-stats.dto.ts
index 05f7eb7..9666296 100644
--- a/apps/api/src/modules/admin/presentation/dto/revenue-stats.dto.ts
+++ b/apps/api/src/modules/admin/presentation/dto/revenue-stats.dto.ts
@@ -1,5 +1,31 @@
 import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger';
-import { IsDateString, IsIn, IsOptional } from 'class-validator';
+import { IsDateString, IsIn, IsOptional, registerDecorator, ValidationArguments, ValidationOptions } from 'class-validator';
+
+function MaxDateRangeDays(maxDays: number, validationOptions?: ValidationOptions) {
+  return function (object: object, propertyName: string) {
+    registerDecorator({
+      name: 'maxDateRangeDays',
+      target: (object as { constructor: new (...args: unknown[]) => unknown }).constructor,
+      propertyName,
+      options: validationOptions,
+      validator: {
+        validate(_value: unknown, args: ValidationArguments) {
+          const dto = args.object as RevenueStatsDto;
+          if (!dto.startDate || !dto.endDate) return true;
+          const start = new Date(dto.startDate);
+          const end = new Date(dto.endDate);
+          const diffMs = end.getTime() - start.getTime();
+          const diffDays = diffMs / (1000 * 60 * 60 * 24);
+          return diffDays >= 0 && diffDays <= maxDays;
+        },
+        defaultMessage(args: ValidationArguments) {
+          return `Date range must not exceed ${(args.constraints as number[])[0]} days`;
+        },
+      },
+      constraints: [maxDays],
+    });
+  };
+}
 
 export class RevenueStatsDto {
   @ApiProperty({ description: 'Start date (ISO 8601)', example: '2025-01-01' })
@@ -8,6 +34,7 @@ export class RevenueStatsDto {
 
   @ApiProperty({ description: 'End date (ISO 8601)', example: '2025-12-31' })
   @IsDateString()
+  @MaxDateRangeDays(366, { message: 'Date range must not exceed 366 days' })
   endDate!: string;
 
   @ApiPropertyOptional({ description: 'Group results by day or month', enum: ['day', 'month'], default: 'month' })