diff --git a/app/Http/Controllers/Admin/Master/Product/ProductVariantController.php b/app/Http/Controllers/Admin/Master/Product/ProductVariantController.php
index ec2e314..c334947 100644
--- a/app/Http/Controllers/Admin/Master/Product/ProductVariantController.php
+++ b/app/Http/Controllers/Admin/Master/Product/ProductVariantController.php
@@ -4,6 +4,7 @@
 
 use App\Http\Controllers\Controller;
 use App\Http\Requests\Admin\Master\Product\ProductVariantRequest;
+use App\Http\Requests\Admin\Master\Product\TransferStockRequest;
 use App\Models\Product;
 use App\Models\ProductVariant;
 use App\Services\Admin\Master\Product\ProductVariantService;
@@ -43,4 +44,13 @@ public function destroy(Product $product, ProductVariant $variant): RedirectResp
             'admin.master.products.index'
         );
     }
+
+    public function transferStock(TransferStockRequest $request, Product $product, ProductVariant $variant): RedirectResponse
+    {
+        return $this->handleAction(
+            fn () => $this->variantService->transferStock($variant, $request->validated()),
+            'Transfer stok berhasil dilakukan.',
+            'admin.master.products.index'
+        );
+    }
 }
diff --git a/app/Http/Requests/Admin/Master/Product/TransferStockRequest.php b/app/Http/Requests/Admin/Master/Product/TransferStockRequest.php
new file mode 100644
index 0000000..caa235a
--- /dev/null
+++ b/app/Http/Requests/Admin/Master/Product/TransferStockRequest.php
@@ -0,0 +1,29 @@
+<?php
+
+namespace App\Http\Requests\Admin\Master\Product;
+
+use Illuminate\Foundation\Http\FormRequest;
+
+class TransferStockRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    public function rules(): array
+    {
+        return [
+            'quantity' => ['required', 'integer', 'min:1'],
+            'description' => ['nullable', 'string', 'max:500'],
+        ];
+    }
+
+    public function attributes(): array
+    {
+        return [
+            'quantity' => 'Jumlah Transfer',
+            'description' => 'Keterangan',
+        ];
+    }
+}
diff --git a/app/Models/ProductVariant.php b/app/Models/ProductVariant.php
index aa6427c..6fa54db 100644
--- a/app/Models/ProductVariant.php
+++ b/app/Models/ProductVariant.php
@@ -45,4 +45,10 @@ public function stokOpnameItems(): HasMany
     {
         return $this->hasMany(StokOpnameItem::class);
     }
+
+    public function stockMutations(): HasMany
+    {
+        return $this->hasMany(StockMutation::class, 'stockable_id')
+            ->where('stockable_type', self::class);
+    }
 }
diff --git a/app/Services/Admin/Master/Product/ProductVariantService.php b/app/Services/Admin/Master/Product/ProductVariantService.php
index 5214258..4a74d8d 100644
--- a/app/Services/Admin/Master/Product/ProductVariantService.php
+++ b/app/Services/Admin/Master/Product/ProductVariantService.php
@@ -5,10 +5,12 @@
 use App\Models\Product;
 use App\Models\ProductPrice;
 use App\Models\ProductVariant;
+use App\Models\StockMutation;
 use App\Services\Concerns\RegistersMedia;
 use App\Services\NotificationService;
 use App\Services\S3PresignedService;
 use Illuminate\Support\Facades\DB;
+use Illuminate\Validation\ValidationException;
 
 class ProductVariantService
 {
@@ -113,4 +115,58 @@ public function getTemporaryUrl(ProductVariant $variant): ?string
 
         return $media ? $this->s3Service->getTemporaryUrl($media->file_name) : null;
     }
+
+    public function transferStock(ProductVariant $variant, array $data): ProductVariant
+    {
+        $quantity = (int) $data['quantity'];
+
+        if ($variant->stock < $quantity) {
+            throw ValidationException::withMessages([
+                'quantity' => "Stok bagus tidak mencukupi. Stok tersedia: {$variant->stock}.",
+            ]);
+        }
+
+        DB::transaction(function () use ($variant, $quantity, $data) {
+            $stockBefore = $variant->stock;
+            $retailBefore = $variant->retail_stock;
+
+            $variant->update([
+                'stock' => $stockBefore - $quantity,
+                'retail_stock' => $retailBefore + $quantity,
+            ]);
+
+            StockMutation::create([
+                'user_id' => auth()->id(),
+                'stockable_type' => ProductVariant::class,
+                'stockable_id' => $variant->id,
+                'type' => 'out',
+                'quantity' => -$quantity,
+                'stock_before' => $stockBefore,
+                'stock_after' => $stockBefore - $quantity,
+                'stock_quality' => 'good',
+                'description' => $data['description'] ?? 'Transfer stok bagus ke stok ecer',
+            ]);
+
+            StockMutation::create([
+                'user_id' => auth()->id(),
+                'stockable_type' => ProductVariant::class,
+                'stockable_id' => $variant->id,
+                'type' => 'in',
+                'quantity' => $quantity,
+                'stock_before' => $retailBefore,
+                'stock_after' => $retailBefore + $quantity,
+                'stock_quality' => 'retail',
+                'description' => $data['description'] ?? 'Transfer stok bagus ke stok ecer',
+            ]);
+        });
+
+        NotificationService::notify(
+            roles: ['Owner', 'Developer', 'Direktur', 'Admin Toko'],
+            title: 'Transfer Stok',
+            body: "{$quantity} unit dari varian \"{$variant->name}\" berhasil ditransfer dari stok bagus ke stok ecer".' oleh '.auth()->user()->full_name.'.',
+            url: route('admin.master.products.index'),
+        );
+
+        return $variant->fresh();
+    }
 }
diff --git a/resources/js/pages/admin/master/product/variant/sub-row.tsx b/resources/js/pages/admin/master/product/variant/sub-row.tsx
index 91b4d75..0a327fe 100644
--- a/resources/js/pages/admin/master/product/variant/sub-row.tsx
+++ b/resources/js/pages/admin/master/product/variant/sub-row.tsx
@@ -1,4 +1,4 @@
-import { Pencil, Trash2 } from 'lucide-react';
+import { ArrowRightLeft, Pencil, Trash2 } from 'lucide-react';
 import { useState } from 'react';
 import { ImagePreviewModal } from '@/components/image-preview-modal';
 import { Button } from '@/components/ui/button';
@@ -16,7 +16,8 @@ import {
     TableHeader,
     TableRow,
 } from '@/components/ui/table';
-import type { Product, ProductVariant } from './columns';
+import type { Product, ProductVariant } from '../columns';
+import { TransferStockDialog } from './transfer-stock-dialog';
 
 function formatCurrency(amount: number): string {
     return new Intl.NumberFormat('id-ID', {
@@ -65,6 +66,10 @@ export function VariantSubRow({
     onDeleteVariantClick: (product: Product, variant: ProductVariant) => void;
 }) {
     const variants = product.product_variants ?? [];
+    const [transferVariant, setTransferVariant] = useState<{
+        product: Product;
+        variant: ProductVariant;
+    } | null>(null);
 
     return (
         <div className="overflow-x-auto">
@@ -84,7 +89,7 @@ export function VariantSubRow({
                         </TableHead>
                         <TableHead className="text-center">Stok Ecer</TableHead>
                         <TableHead>Harga</TableHead>
-                        <TableHead className="w-[80px] text-center">
+                        <TableHead className="w-[120px] text-center">
                             Aksi
                         </TableHead>
                     </TableRow>
@@ -151,6 +156,25 @@ export function VariantSubRow({
                                 <TableCell>
                                     <TooltipProvider>
                                         <div className="flex items-center justify-center gap-1">
+                                            <Tooltip>
+                                                <TooltipTrigger asChild>
+                                                    <Button
+                                                        variant="ghost"
+                                                        size="icon"
+                                                        onClick={() =>
+                                                            setTransferVariant({
+                                                                product,
+                                                                variant,
+                                                            })
+                                                        }
+                                                    >
+                                                        <ArrowRightLeft className="h-4 w-4" />
+                                                    </Button>
+                                                </TooltipTrigger>
+                                                <TooltipContent side="top">
+                                                    Transfer Stok
+                                                </TooltipContent>
+                                            </Tooltip>
                                             <Tooltip>
                                                 <TooltipTrigger asChild>
                                                     <Button
@@ -197,6 +221,19 @@ export function VariantSubRow({
                     )}
                 </TableBody>
             </Table>
+
+            {transferVariant && (
+                <TransferStockDialog
+                    open={transferVariant !== null}
+                    onOpenChange={(open) => {
+                        if (!open) {
+                            setTransferVariant(null);
+                        }
+                    }}
+                    product={transferVariant.product}
+                    variant={transferVariant.variant}
+                />
+            )}
         </div>
     );
 }
diff --git a/resources/js/pages/admin/master/product/variant/transfer-stock-dialog.tsx b/resources/js/pages/admin/master/product/variant/transfer-stock-dialog.tsx
new file mode 100644
index 0000000..d174ba2
--- /dev/null
+++ b/resources/js/pages/admin/master/product/variant/transfer-stock-dialog.tsx
@@ -0,0 +1,121 @@
+import { Form } from '@inertiajs/react';
+import InputError from '@/components/input-error';
+import { Button } from '@/components/ui/button';
+import {
+    Dialog,
+    DialogContent,
+    DialogFooter,
+    DialogHeader,
+    DialogTitle,
+} from '@/components/ui/dialog';
+import { Input } from '@/components/ui/input';
+import { Label } from '@/components/ui/label';
+import { Textarea } from '@/components/ui/textarea';
+import { transferStock } from '@/routes/admin/master/products/variants';
+import type { Product, ProductVariant } from '../columns';
+
+type TransferStockDialogProps = {
+    open: boolean;
+    onOpenChange: (open: boolean) => void;
+    product: Product;
+    variant: ProductVariant;
+};
+
+export function TransferStockDialog({
+    open,
+    onOpenChange,
+    product,
+    variant,
+}: TransferStockDialogProps) {
+    return (
+        <Dialog open={open} onOpenChange={onOpenChange}>
+            <DialogContent>
+                <Form
+                    action={transferStock.post({
+                        product: product.id,
+                        variant: variant.id,
+                    })}
+                    resetOnSuccess
+                    onSuccess={() => onOpenChange(false)}
+                >
+                    {({ errors, processing }) => (
+                        <>
+                            <DialogHeader>
+                                <DialogTitle>
+                                    Transfer Stok Bagus → Stok Ecer
+                                </DialogTitle>
+                            </DialogHeader>
+                            <div className="grid gap-4 py-4">
+                                <div className="grid gap-2">
+                                    <Label className="text-sm text-muted-foreground">
+                                        Produk
+                                    </Label>
+                                    <p className="text-sm font-medium">
+                                        {product.name}
+                                    </p>
+                                </div>
+                                <div className="grid gap-2">
+                                    <Label className="text-sm text-muted-foreground">
+                                        Varian
+                                    </Label>
+                                    <p className="text-sm font-medium">
+                                        {variant.name}
+                                    </p>
+                                </div>
+                                <div className="grid gap-2">
+                                    <Label className="text-sm text-muted-foreground">
+                                        Stok Bagus Tersedia
+                                    </Label>
+                                    <p className="text-sm font-medium">
+                                        {variant.stock}
+                                    </p>
+                                </div>
+                                <div className="grid gap-2">
+                                    <Label htmlFor="quantity">
+                                        Jumlah Transfer{' '}
+                                        <span className="text-destructive">
+                                            *
+                                        </span>
+                                    </Label>
+                                    <Input
+                                        id="quantity"
+                                        name="quantity"
+                                        type="number"
+                                        min={1}
+                                        max={variant.stock}
+                                        placeholder="Masukkan jumlah transfer"
+                                    />
+                                    <InputError message={errors.quantity} />
+                                </div>
+                                <div className="grid gap-2">
+                                    <Label htmlFor="description">
+                                        Keterangan
+                                    </Label>
+                                    <Textarea
+                                        id="description"
+                                        name="description"
+                                        placeholder="Masukkan keterangan"
+                                        rows={3}
+                                    />
+                                    <InputError message={errors.description} />
+                                </div>
+                            </div>
+                            <DialogFooter>
+                                <Button
+                                    type="button"
+                                    variant="outline"
+                                    onClick={() => onOpenChange(false)}
+                                >
+                                    Batal
+                                </Button>
+                                <Button type="submit" disabled={processing}>
+                                    {processing ? 'Menyimpan...' : 'Transfer'}
+                                </Button>
+                            </DialogFooter>
+                        </>
+                    )}
+                </Form>
+            </DialogContent>
+        </Dialog>
+    );
+}
diff --git a/routes/web.php b/routes/web.php
index 471d3a7..03e3112 100644
--- a/routes/web.php
+++ b/routes/web.php
@@ -37,6 +37,7 @@
         Route::delete('products/{product}/variants/{variant}', [ProductVariantController::class, 'destroy'])->name('products.variants.destroy');
         Route::get('products/{product}/variants/{variant}/edit', [ProductVariantController::class, 'edit'])->name('products.variants.edit');
         Route::put('products/{product}/variants/{variant}', [ProductVariantController::class, 'update'])->name('products.variants.update');
+        Route::post('products/{product}/variants/{variant}/transfer-stock', [ProductVariantController::class, 'transferStock'])->name('products.variants.transfer-stock');
         Route::resource('suppliers', SupplierController::class)->except(['show', 'create', 'edit']);
         Route::resource('customers', CustomerController::class)->except(['show', 'create', 'edit']);
     });
diff --git a/tests/Feature/Admin/Master/ProductTest.php b/tests/Feature/Admin/Master/ProductTest.php
index 843d371..1b6cac7 100644
--- a/tests/Feature/Admin/Master/ProductTest.php
+++ b/tests/Feature/Admin/Master/ProductTest.php
@@ -4,6 +4,7 @@
 use App\Models\Product;
 use App\Models\ProductPrice;
 use App\Models\ProductVariant;
+use App\Models\StockMutation;
 use App\Models\User;
 use Illuminate\Foundation\Testing\RefreshDatabase;
 use Illuminate\Support\Facades\DB;
@@ -2266,3 +2267,262 @@ function allPriceTypes(): array
     $response = $this->delete(route('admin.master.products.variants.destroy', [$product, 99999]));
     $response->assertStatus(404);
 });
+
+/*
+|--------------------------------------------------------------------------
+| TRANSFER STOCK (BAGUS -> ECER)
+|--------------------------------------------------------------------------
+*/
+
+test('guest cannot transfer stock', function () {
+    $product = Product::factory()->create();
+    $variant = ProductVariant::factory()->for($product)->create(['stock' => 100]);
+
+    $response = $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), [
+        'quantity' => 10,
+    ]);
+
+    $response->assertRedirect(route('login'));
+});
+
+test('authenticated user can transfer stock', function () {
+    $user = User::factory()->create();
+    $this->actingAs($user);
+
+    $product = Product::factory()->create();
+    $variant = ProductVariant::factory()->for($product)->create([
+        'stock' => 100,
+        'retail_stock' => 20,
+    ]);
+
+    $response = $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), [
+        'quantity' => 10,
+    ]);
+
+    $response->assertRedirect();
+    $variant->refresh();
+    expect($variant->stock)->toBe(90);
+    expect($variant->retail_stock)->toBe(30);
+});
+
+test('transfer stock creates two stock mutation records', function () {
+    $user = User::factory()->create();
+    $this->actingAs($user);
+
+    $product = Product::factory()->create();
+    $variant = ProductVariant::factory()->for($product)->create(['stock' => 100, 'retail_stock' => 20]);
+
+    $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), [
+        'quantity' => 10,
+    ]);
+
+    $this->assertDatabaseCount('stock_mutations', 2);
+
+    $outMutation = StockMutation::where('stockable_id', $variant->id)->where('type', 'out')->first();
+    expect($outMutation)->not->toBeNull();
+    expect((float) $outMutation->quantity)->toBe(-10.0);
+    expect((float) $outMutation->stock_before)->toBe(100.0);
+    expect((float) $outMutation->stock_after)->toBe(90.0);
+    expect($outMutation->stock_quality)->toBe('good');
+    expect($outMutation->user_id)->toBe($user->id);
+
+    $inMutation = StockMutation::where('stockable_id', $variant->id)->where('type', 'in')->first();
+    expect($inMutation)->not->toBeNull();
+    expect((float) $inMutation->quantity)->toBe(10.0);
+    expect((float) $inMutation->stock_before)->toBe(20.0);
+    expect((float) $inMutation->stock_after)->toBe(30.0);
+    expect($inMutation->stock_quality)->toBe('retail');
+    expect($inMutation->user_id)->toBe($user->id);
+});
+
+test('transfer stock with description saves to mutations', function () {
+    $user = User::factory()->create();
+    $this->actingAs($user);
+
+    $product = Product::factory()->create();
+    $variant = ProductVariant::factory()->for($product)->create(['stock' => 50, 'retail_stock' => 10]);
+
+    $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), [
+        'quantity' => 5,
+        'description' => 'Transfer untuk display toko',
+    ]);
+
+    $mutation = StockMutation::where('stockable_id', $variant->id)->where('type', 'out')->first();
+    expect($mutation->description)->toBe('Transfer untuk display toko');
+});
+
+test('transfer stock without description uses default', function () {
+    $user = User::factory()->create();
+    $this->actingAs($user);
+
+    $product = Product::factory()->create();
+    $variant = ProductVariant::factory()->for($product)->create(['stock' => 50, 'retail_stock' => 10]);
+
+    $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), [
+        'quantity' => 5,
+    ]);
+
+    $mutation = StockMutation::where('stockable_id', $variant->id)->where('type', 'out')->first();
+    expect($mutation->description)->toBe('Transfer stok bagus ke stok ecer');
+});
+
+test('transfer stock quantity must be provided', function () {
+    $user = User::factory()->create();
+    $this->actingAs($user);
+
+    $product = Product::factory()->create();
+    $variant = ProductVariant::factory()->for($product)->create(['stock' => 100]);
+
+    $response = $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), []);
+
+    $variant->refresh();
+    expect($variant->stock)->toBe(100);
+    $this->assertDatabaseCount('stock_mutations', 0);
+});
+
+test('transfer stock quantity must be integer', function () {
+    $user = User::factory()->create();
+    $this->actingAs($user);
+
+    $product = Product::factory()->create();
+    $variant = ProductVariant::factory()->for($product)->create(['stock' => 100]);
+
+    $response = $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), [
+        'quantity' => 'abc',
+    ]);
+
+    $variant->refresh();
+    expect($variant->stock)->toBe(100);
+    $this->assertDatabaseCount('stock_mutations', 0);
+});
+
+test('transfer stock quantity must be at least 1', function () {
+    $user = User::factory()->create();
+    $this->actingAs($user);
+
+    $product = Product::factory()->create();
+    $variant = ProductVariant::factory()->for($product)->create(['stock' => 100]);
+
+    $response = $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), [
+        'quantity' => 0,
+    ]);
+
+    $variant->refresh();
+    expect($variant->stock)->toBe(100);
+    $this->assertDatabaseCount('stock_mutations', 0);
+});
+
+test('transfer stock quantity cannot exceed available stock', function () {
+    $user = User::factory()->create();
+    $this->actingAs($user);
+
+    $product = Product::factory()->create();
+    $variant = ProductVariant::factory()->for($product)->create(['stock' => 10, 'retail_stock' => 5]);
+
+    $response = $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), [
+        'quantity' => 15,
+    ]);
+
+    $variant->refresh();
+    expect($variant->stock)->toBe(10);
+    expect($variant->retail_stock)->toBe(5);
+    $this->assertDatabaseCount('stock_mutations', 0);
+});
+
+test('transfer stock exactly equal to available stock is allowed', function () {
+    $user = User::factory()->create();
+    $this->actingAs($user);
+
+    $product = Product::factory()->create();
+    $variant = ProductVariant::factory()->for($product)->create(['stock' => 10, 'retail_stock' => 5]);
+
+    $response = $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), [
+        'quantity' => 10,
+    ]);
+
+    $response->assertRedirect();
+    $variant->refresh();
+    expect($variant->stock)->toBe(0);
+    expect($variant->retail_stock)->toBe(15);
+});
+
+test('transfer stock from zero stock is rejected', function () {
+    $user = User::factory()->create();
+    $this->actingAs($user);
+
+    $product = Product::factory()->create();
+    $variant = ProductVariant::factory()->for($product)->create(['stock' => 0, 'retail_stock' => 0]);
+
+    $response = $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), [
+        'quantity' => 1,
+    ]);
+
+    $variant->refresh();
+    expect($variant->stock)->toBe(0);
+    expect($variant->retail_stock)->toBe(0);
+    $this->assertDatabaseCount('stock_mutations', 0);
+});
+
+test('transfer stock multiple times sequentially', function () {
+    $user = User::factory()->create();
+    $this->actingAs($user);
+
+    $product = Product::factory()->create();
+    $variant = ProductVariant::factory()->for($product)->create(['stock' => 100, 'retail_stock' => 0]);
+
+    $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), ['quantity' => 20]);
+    $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), ['quantity' => 30]);
+    $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), ['quantity' => 10]);
+
+    $variant->refresh();
+    expect($variant->stock)->toBe(40);
+    expect($variant->retail_stock)->toBe(60);
+    $this->assertDatabaseCount('stock_mutations', 6);
+});
+
+test('transfer stock does not affect reject_stock', function () {
+    $user = User::factory()->create();
+    $this->actingAs($user);
+
+    $product = Product::factory()->create();
+    $variant = ProductVariant::factory()->for($product)->create([
+        'stock' => 100,
+        'reject_stock' => 50,
+        'retail_stock' => 10,
+    ]);
+
+    $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), [
+        'quantity' => 25,
+    ]);
+
+    $variant->refresh();
+    expect($variant->stock)->toBe(75);
+    expect($variant->reject_stock)->toBe(50);
+    expect($variant->retail_stock)->toBe(35);
+});
+
+test('transfer stock on non-existent variant returns 404', function () {
+    $user = User::factory()->create();
+    $this->actingAs($user);
+
+    $product = Product::factory()->create();
+
+    $response = $this->post(route('admin.master.products.variants.transfer-stock', [$product, 99999]), [
+        'quantity' => 10,
+    ]);
+    $response->assertStatus(404);
+});
+
+test('transfer stock redirects to product index', function () {
+    $user = User::factory()->create();
+    $this->actingAs($user);
+
+    $product = Product::factory()->create();
+    $variant = ProductVariant::factory()->for($product)->create(['stock' => 100]);
+
+    $response = $this->post(route('admin.master.products.variants.transfer-stock', [$product, $variant]), [
+        'quantity' => 10,
+    ]);
+
+    $response->assertRedirect(route('admin.master.products.index'));
+});