diff --git a/PortfolioJournal/Models/CoreData/PortfolioJournal.xcdatamodeld/PortfolioJournal.xcdatamodel/contents b/PortfolioJournal/Models/CoreData/PortfolioJournal.xcdatamodeld/PortfolioJournal.xcdatamodel/contents
index 1487447..1b72142 100644
--- a/PortfolioJournal/Models/CoreData/PortfolioJournal.xcdatamodeld/PortfolioJournal.xcdatamodel/contents
+++ b/PortfolioJournal/Models/CoreData/PortfolioJournal.xcdatamodeld/PortfolioJournal.xcdatamodel/contents
@@ -100,6 +100,7 @@
         <attribute name="createdAt" optional="YES" attributeType="Date" usesScalarValueType="NO"/>
         <attribute name="date" optional="YES" attributeType="Date" usesScalarValueType="NO"/>
         <attribute name="id" optional="YES" attributeType="UUID" usesScalarValueType="NO"/>
+        <attribute name="isEstimated" optional="YES" attributeType="Boolean" defaultValueString="NO" usesScalarValueType="YES"/>
         <attribute name="notes" optional="YES" attributeType="String"/>
         <attribute name="value" optional="YES" attributeType="Decimal"/>
         <relationship name="source" optional="YES" maxCount="1" deletionRule="Nullify" destinationEntity="InvestmentSource" inverseName="snapshots" inverseEntity="InvestmentSource"/>
diff --git a/PortfolioJournal/Models/CoreData/Snapshot+CoreDataClass.swift b/PortfolioJournal/Models/CoreData/Snapshot+CoreDataClass.swift
index 9d39c26..2758719 100644
--- a/PortfolioJournal/Models/CoreData/Snapshot+CoreDataClass.swift
+++ b/PortfolioJournal/Models/CoreData/Snapshot+CoreDataClass.swift
@@ -18,6 +18,10 @@ public class Snapshot: NSManagedObject, Identifiable {
     @NSManaged public var value: NSDecimalNumber?
     @NSManaged public var contribution: NSDecimalNumber?
     @NSManaged public var notes: String?
+    /// True for auto-generated (interpolated) snapshots that fill a gap between two
+    /// real snapshots. Estimated snapshots are shown with a distinct marker and can
+    /// be removed in bulk. Defaults to false (model default) for all real snapshots.
+    @NSManaged public var isEstimated: Bool
     @objc public var createdAt: Date {
         get { safeValue(forKey: "createdAt", fallback: .distantPast) }
         set { setManagedValue(newValue, forKey: "createdAt") }
diff --git a/PortfolioJournal/Repositories/AccountRepository.swift b/PortfolioJournal/Repositories/AccountRepository.swift
index 396bbe9..5002017 100644
--- a/PortfolioJournal/Repositories/AccountRepository.swift
+++ b/PortfolioJournal/Repositories/AccountRepository.swift
@@ -96,9 +96,12 @@ class AccountRepository: ObservableObject {
             return existing
         }
 
-        // No accounts exist, create Default account
+        // No accounts exist, create Default account.
+        // Use a DETERMINISTIC id so every device creates the same CloudKit record
+        // instead of a per-device duplicate (root-cause fix for the dedup pile-up).
         let defaultCurrency = AppSettings.getOrCreate(in: context).currency
         let account = Account(context: context)
+        account.id = Account.defaultAccountStableID
         account.name = Account.defaultAccountName
         account.currency = defaultCurrency
         account.inputMode = InputMode.simple.rawValue
diff --git a/PortfolioJournal/Repositories/CategoryRepository.swift b/PortfolioJournal/Repositories/CategoryRepository.swift
index 5ee5db6..1435caf 100644
--- a/PortfolioJournal/Repositories/CategoryRepository.swift
+++ b/PortfolioJournal/Repositories/CategoryRepository.swift
@@ -109,6 +109,8 @@ class CategoryRepository: ObservableObject {
             }
 
             let category = Category(context: context)
+            // Deterministic id → same CloudKit record on every device (no duplicates).
+            category.id = Category.stableID(for: categoryData.name)
             category.name = categoryData.name
             category.colorHex = categoryData.colorHex
             category.icon = categoryData.icon
diff --git a/PortfolioJournal/ViewModels/SettingsViewModel.swift b/PortfolioJournal/ViewModels/SettingsViewModel.swift
index 4c62bc1..c172dbc 100644
--- a/PortfolioJournal/ViewModels/SettingsViewModel.swift
+++ b/PortfolioJournal/ViewModels/SettingsViewModel.swift
@@ -353,6 +353,7 @@ class SettingsViewModel: ObservableObject {
             if accountCount == 0 {
                 let defaultCurrency = AppSettings.getOrCreate(in: context).currency
                 let account = Account(context: context)
+                account.id = Account.defaultAccountStableID
                 account.name = Account.defaultAccountName
                 account.currency = defaultCurrency
                 account.inputMode = InputMode.simple.rawValue