diff --git a/index.html b/index.html
index 5d170bf..f1a6df5 100644
--- a/index.html
+++ b/index.html
@@ -2125,6 +2125,7 @@ function updateROI() {
     document.getElementById('roiBarPhase').style.width = '0%';
     document.querySelectorAll('.roi-ladder-step').forEach(el => el.classList.remove('active', 'passed'));
     document.getElementById('roiMilestones').innerHTML = '<div style="color:var(--text-muted);font-size:0.85rem;padding:10px 0;">Enter your numbers above to see your progress 🚀</div>';
+    saveROIData(deposits, earned, phase, cyclesDone);
     return;
   }
 
@@ -2220,6 +2221,30 @@ function updateROI() {
       </div>
     </div>
   `).join('');
+
+  // Save to localStorage
+  saveROIData(deposits, earned, phase, cyclesDone);
+}
+
+// ─── localStorage persistence ──────────────────────────
+function getROIStorageKey() {
+  const ref = getRefFromURL() || 'cryptoteambuild';
+  return 'cbp_roi_' + ref;
+}
+
+function saveROIData(deposits, earned, phase, cyclesDone) {
+  const key = getROIStorageKey();
+  const data = { deposits, earned, phase, cyclesDone };
+  try { localStorage.setItem(key, JSON.stringify(data)); } catch(e) {}
+}
+
+function loadROIData() {
+  const key = getROIStorageKey();
+  try {
+    const raw = localStorage.getItem(key);
+    if (raw) return JSON.parse(raw);
+  } catch(e) {}
+  return null;
 }
 
 // Wire up ROI inputs
@@ -2229,6 +2254,15 @@ function updateROI() {
   el.addEventListener('change', updateROI);
 });
 
+// Load saved data on page load
+const saved = loadROIData();
+if (saved) {
+  document.getElementById('roiDeposits').value = saved.deposits || '';
+  document.getElementById('roiTotalEarned').value = saved.earned || '';
+  if (saved.phase) document.getElementById('roiPhase').value = saved.phase;
+  document.getElementById('roiCyclesDone').value = saved.cyclesDone !== undefined ? saved.cyclesDone : '';
+}
+
 // Initial render on page load (delayed to ensure DOM is ready)
 setTimeout(updateROI, 150);
 </script>