diff --git a/app/Rules/QuantityValidationRule.php b/app/Rules/QuantityValidationRule.php
index ffee127..91bebe2 100644
--- a/app/Rules/QuantityValidationRule.php
+++ b/app/Rules/QuantityValidationRule.php
@@ -15,11 +15,13 @@ class QuantityValidationRule implements ValidationRule
     public function __construct(
         protected Portfolio $portfolio, 
         protected string $symbol, 
-        protected string $transactionType
+        protected string $transactionType,
+        protected string $date
     ) {
         $this->portfolio = $portfolio;
-        $this->symbol = $symbol;
+        $this->symbol = $symbol; 
         $this->transactionType = $transactionType;
+        $this->date = $date;
     }
 
     /**
@@ -33,9 +35,21 @@ class QuantityValidationRule implements ValidationRule
     public function validate(string $attribute, mixed $value, \Closure $fail): void
     {
         if ($this->transactionType == 'SELL') {
-            $holding = $this->portfolio->holdings()->symbol($this->symbol)->first();
-            $maxQuantity = $holding ? $holding->quantity : 0;
-            
+
+            $purchase_qty = $this->portfolio->transactions()
+                                        ->symbol($this->symbol)
+                                        ->buy()
+                                        ->beforeDate($this->date)
+                                        ->sum('quantity');
+
+            $sales_qty = $this->portfolio->transactions()
+                                        ->symbol($this->symbol)
+                                        ->sell()
+                                        ->beforeDate($this->date)
+                                        ->sum('quantity');
+   
+            $maxQuantity = $purchase_qty - $sales_qty;
+
             if ($value > $maxQuantity) {
                 $fail(__('The quantity must not be greater than the available quantity.'));
             }
diff --git a/resources/views/livewire/manage-transaction-form.blade.php b/resources/views/livewire/manage-transaction-form.blade.php
index 8493ee3..95586bd 100644
--- a/resources/views/livewire/manage-transaction-form.blade.php
+++ b/resources/views/livewire/manage-transaction-form.blade.php
@@ -40,7 +40,7 @@ new class extends Component {
                 'required', 
                 'numeric', 
                 'min:0', 
-                new QuantityValidationRule($this->portfolio, $this->symbol, $this->transaction_type)
+                new QuantityValidationRule($this->portfolio, $this->symbol, $this->transaction_type, $this->date)
             ],
             'cost_basis' => 'exclude_if:transaction_type,SELL|min:0|numeric',
             'sale_price' => 'exclude_if:transaction_type,BUY|min:0|numeric',