diff --git a/pages/cards.js b/pages/cards.js
index a8478ea..d485bda 100644
--- a/pages/cards.js
+++ b/pages/cards.js
@@ -105,6 +105,28 @@ export default function Cards() {
     }
   };
 
+  // Load user's favorited cards
+  const loadFavoritedCards = async () => {
+    try {
+      const token = localStorage.getItem('auth_token');
+      if (!token) return;
+
+      const response = await fetch('/api/favorites?type=card', {
+        headers: {
+          'Authorization': `Bearer ${token}`
+        }
+      });
+
+      if (response.ok) {
+        const data = await response.json();
+        const favoriteIds = new Set(data.favorites.map(fav => parseInt(fav.item_id)));
+        setFavoritedCards(favoriteIds);
+      }
+    } catch (error) {
+      console.error('Error loading favorited cards:', error);
+    }
+  };
+
   // Initial load
   useEffect(() => {
     setPagination(prev => ({ ...prev, page: 1 }));
@@ -112,6 +134,7 @@ export default function Cards() {
     setHasMore(true);
     hasMoreRef.current = true;
     fetchCards(false);
+    loadFavoritedCards(); // Load user's favorites
   }, [selectedTCG, selectedRarity, selectedSet, selectedValueRange]);
 
   // Handle search with debounce
@@ -369,14 +392,88 @@ export default function Cards() {
     alert(`Adding ${cards.length} cards to deck (functionality coming soon)`);
   };
 
-  const handleBulkMarkAsOwned = (cards) => {
-    console.log('Marking as owned:', cards);
-    alert(`Marking ${cards.length} cards as owned (functionality coming soon)`);
+  const handleBulkMarkAsOwned = async (cards) => {
+    try {
+      const token = localStorage.getItem('auth_token');
+      if (!token) {
+        alert('Please log in to mark cards as owned');
+        return;
+      }
+
+      let successCount = 0;
+      for (const card of cards) {
+        try {
+          const response = await fetch(`/api/cards/${card.id}/ownership`, {
+            method: 'POST',
+            headers: {
+              'Content-Type': 'application/json',
+              'Authorization': `Bearer ${token}`
+            },
+            body: JSON.stringify({ quantity: 1 })
+          });
+
+          if (response.ok) {
+            successCount++;
+          }
+        } catch (error) {
+          console.error(`Error marking card ${card.id} as owned:`, error);
+        }
+      }
+
+      if (successCount === cards.length) {
+        alert(`Successfully marked ${cards.length} cards as owned!`);
+      } else {
+        alert(`Marked ${successCount} out of ${cards.length} cards as owned. Some operations may have failed.`);
+      }
+
+      // Clear selection after successful operation
+      setSelectedCards([]);
+    } catch (error) {
+      console.error('Error in bulk mark as owned:', error);
+      alert('Failed to mark cards as owned. Please try again.');
+    }
   };
 
-  const handleBulkRemoveFromOwned = (cards) => {
-    console.log('Removing from owned:', cards);
-    alert(`Removing ${cards.length} cards from owned (functionality coming soon)`);
+  const handleBulkRemoveFromOwned = async (cards) => {
+    try {
+      const token = localStorage.getItem('auth_token');
+      if (!token) {
+        alert('Please log in to remove cards from owned');
+        return;
+      }
+
+      let successCount = 0;
+      for (const card of cards) {
+        try {
+          const response = await fetch(`/api/cards/${card.id}/ownership`, {
+            method: 'POST',
+            headers: {
+              'Content-Type': 'application/json',
+              'Authorization': `Bearer ${token}`
+            },
+            body: JSON.stringify({ quantity: 0 })
+          });
+
+          if (response.ok) {
+            successCount++;
+          }
+        } catch (error) {
+          console.error(`Error removing card ${card.id} from owned:`, error);
+        }
+      }
+
+      if (successCount === cards.length) {
+        alert(`Successfully removed ${cards.length} cards from owned!`);
+      } else {
+        alert(`Removed ${successCount} out of ${cards.length} cards from owned. Some operations may have failed.`);
+      }
+
+      // Clear selection after successful operation
+      setSelectedCards([]);
+    } catch (error) {
+      console.error('Error in bulk remove from owned:', error);
+      alert('Failed to remove cards from owned. Please try again.');
+    }
   };
 
   const handleBulkFavorite = async (cards) => {