diff --git a/app/models/account/entry.rb b/app/models/account/entry.rb
index 345fe26bcb2..4ee0f9f686e 100644
--- a/app/models/account/entry.rb
+++ b/app/models/account/entry.rb
@@ -200,6 +200,11 @@ def create_trend
     end
 
     def trade_valid?
+      if account_trade.currency != currency
+        # i18n-tasks-use t('activerecord.errors.models.account/entry.attributes.base.currency_mismatch')
+        errors.add(:base, :currency_mismatch)
+      end
+
       if account_trade.sell?
         current_qty = account.holding_qty(account_trade.security)
 
diff --git a/config/locales/models/account/entry/en.yml b/config/locales/models/account/entry/en.yml
index e1e0605e755..84f8d5c2242 100644
--- a/config/locales/models/account/entry/en.yml
+++ b/config/locales/models/account/entry/en.yml
@@ -6,5 +6,6 @@ en:
         account/entry:
           attributes:
             base:
+              currency_mismatch: Entry currency must match trade currency
               invalid_sell_quantity: cannot sell %{sell_qty} shares of %{ticker} because
                 you only own %{current_qty} shares
diff --git a/test/models/account/entry_test.rb b/test/models/account/entry_test.rb
index e1bfa6da1a2..633585d7eab 100644
--- a/test/models/account/entry_test.rb
+++ b/test/models/account/entry_test.rb
@@ -110,9 +110,22 @@ class Account::EntryTest < ActiveSupport::TestCase
         amount: 100,
         currency: "USD",
         name: "Sell 10 shares of AMZN",
-        entryable: Account::Trade.new(qty: -10, price: 200, security: security)
+        entryable: Account::Trade.new(qty: -10, price: 200, currency: "USD", security: security)
     end
 
     assert_match /cannot sell 10.0 shares of AAPL because you only own 0.0 shares/, error.message
   end
+
+  # Trade has a denormalized currency field that must match its parent Entry currency
+  test "trade must have same currency as entry" do
+    account = accounts(:investment)
+    assert_raises ActiveRecord::RecordInvalid do
+      account.entries.create! \
+        date: Date.current,
+        amount: 100,
+        currency: "USD",
+        name: "Test",
+        entryable: Account::Trade.new(qty: 10, price: 10, currency: "EUR", security: securities(:aapl))
+    end
+  end
 end
diff --git a/test/models/account/holding/syncer_test.rb b/test/models/account/holding/syncer_test.rb
index fd917a0d2c8..7cd27efdba6 100644
--- a/test/models/account/holding/syncer_test.rb
+++ b/test/models/account/holding/syncer_test.rb
@@ -33,16 +33,16 @@ class Account::Holding::SyncerTest < ActiveSupport::TestCase
     create_trade(security1, account: @account, qty: -10, date: Date.current) # sell 10 shares of AMZN
 
     expected = [
-      { ticker: "AMZN", qty: 10, price: 214, amount: 10 * 214, date: 2.days.ago.to_date },
-      { ticker: "AMZN", qty: 12, price: 215, amount: 12 * 215, date: 1.day.ago.to_date },
-      { ticker: "AMZN", qty: 2, price: 216, amount: 2 * 216, date: Date.current },
-      { ticker: "NVDA", qty: 20, price: 122, amount: 20 * 122, date: 1.day.ago.to_date },
-      { ticker: "NVDA", qty: 20, price: 124, amount: 20 * 124, date: Date.current }
+      { ticker: "AMZN", qty: 10, price: 214, amount: 10 * 214, date: 2.days.ago.to_date, currency: "USD" },
+      { ticker: "AMZN", qty: 12, price: 215, amount: 12 * 215, date: 1.day.ago.to_date, currency: "USD" },
+      { ticker: "AMZN", qty: 2, price: 216, amount: 2 * 216, date: Date.current, currency: "USD" },
+      { ticker: "NVDA", qty: 20, price: 122, amount: 20 * 122, date: 1.day.ago.to_date, currency: "USD" },
+      { ticker: "NVDA", qty: 20, price: 124, amount: 20 * 124, date: Date.current, currency: "USD" }
     ]
 
     run_sync_for(@account)
 
-    assert_holdings(expected)
+    assert_holdings(expected, @account)
   end
 
   test "generates holdings with prices" do
@@ -55,12 +55,12 @@ class Account::Holding::SyncerTest < ActiveSupport::TestCase
     create_trade(amzn, account: @account, qty: 10, date: Date.current, price: 215)
 
     expected = [
-      { ticker: "AMZN", qty: 10, price: 215, amount: 10 * 215, date: Date.current }
+      { ticker: "AMZN", qty: 10, price: 215, amount: 10 * 215, date: Date.current, currency: "USD" }
     ]
 
     run_sync_for(@account)
 
-    assert_holdings(expected)
+    assert_holdings(expected, @account)
   end
 
   test "generates all holdings even when missing security prices" do
@@ -72,9 +72,9 @@ class Account::Holding::SyncerTest < ActiveSupport::TestCase
     # 1 day ago — finds daily price, uses it
     # Today — no daily price, no entry, so price and amount are `nil`
     expected = [
-      { ticker: "AMZN", qty: 10, price: 210, amount: 10 * 210, date: 2.days.ago.to_date },
-      { ticker: "AMZN", qty: 10, price: 215, amount: 10 * 215, date: 1.day.ago.to_date },
-      { ticker: "AMZN", qty: 10, price: nil, amount: nil, date: Date.current }
+      { ticker: "AMZN", qty: 10, price: 210, amount: 10 * 210, date: 2.days.ago.to_date, currency: "USD" },
+      { ticker: "AMZN", qty: 10, price: 215, amount: 10 * 215, date: 1.day.ago.to_date, currency: "USD" },
+      { ticker: "AMZN", qty: 10, price: nil, amount: nil, date: Date.current, currency: "USD" }
     ]
 
     Security::Price.expects(:find_prices)
@@ -86,25 +86,84 @@ class Account::Holding::SyncerTest < ActiveSupport::TestCase
 
     run_sync_for(@account)
 
-    assert_holdings(expected)
+    assert_holdings(expected, @account)
+  end
+
+  # TODO
+  test "syncs multi currency trade" do
+    price_currency = "USD" # Stock price fetched from provider is USD
+    trade_currency = "EUR" # Trade performed in EUR
+
+    amzn = create_security("AMZN", prices: [
+      { date: 1.day.ago.to_date, price: 200, currency: price_currency },
+      { date: Date.current, price: 210, currency: price_currency }
+    ])
+
+    create_trade(amzn, account: @account, qty: 10, date: 1.day.ago.to_date, price: 180, currency: trade_currency)
+
+    # We expect holding to be generated in the account's currency (which is what shows to the user)
+    expected = [
+      { ticker: "AMZN", qty: 10, price: 200, amount: 10 * 200, date: 1.day.ago.to_date, currency: "USD" },
+      { ticker: "AMZN", qty: 10, price: 210, amount: 10 * 210, date: Date.current, currency: "USD" }
+    ]
+
+    run_sync_for(@account)
+
+    assert_holdings(expected, @account)
+  end
+
+  # TODO
+  test "syncs foreign currency investment account" do
+    # Account is EUR, but family is USD.  Must show holdings on account page in EUR, but aggregate holdings in USD for family views
+    @account.update! currency: "EUR"
+    assert_not_equal @account.currency, @account.family.currency
+
+    price_currency = "USD" # Stock price fetched from provider is USD
+    trade_currency = "EUR" # Trade performed in EUR
+
+    amzn = create_security("AMZN", prices: [
+      { date: 1.day.ago.to_date, price: 200, currency: price_currency },
+      { date: Date.current, price: 210, currency: price_currency }
+    ])
+
+    create_trade(amzn, account: @account, qty: 10, date: 1.day.ago.to_date, price: 200, currency: trade_currency)
+
+    ExchangeRate.create! date: 1.day.ago.to_date, from_currency: "USD", to_currency: "EUR", rate: 0.9
+    ExchangeRate.create! date: Date.current, from_currency: "USD", to_currency: "EUR", rate: 0.9
+
+    expected = [
+      # Holdings in the account's currency for the account view
+      { ticker: "AMZN", qty: 10, price: 200 * 0.9, amount: 10 * 200 * 0.9, date: 1.day.ago.to_date, currency: "EUR" },
+      { ticker: "AMZN", qty: 10, price: 200 * 0.9, amount: 10 * 200 * 0.9, date: Date.current, currency: "EUR" },
+
+      # Holdings in the family's currency for aggregated calculations
+      { ticker: "AMZN", qty: 10, price: 200, amount: 10 * 200, date: 1.day.ago.to_date, currency: "USD" },
+      { ticker: "AMZN", qty: 10, price: 200, amount: 10 * 200, date: Date.current, currency: "USD" }
+    ]
+
+    run_sync_for(@account)
+
+    assert_holdings(expected, @account)
   end
 
   private
 
-    def assert_holdings(expected_holdings)
-      holdings = @account.holdings.includes(:security).to_a
+    def assert_holdings(expected_holdings, account)
+      holdings = account.holdings.includes(:security).to_a
       expected_holdings.each do |expected_holding|
         actual_holding = holdings.find { |holding| holding.security.ticker == expected_holding[:ticker] && holding.date == expected_holding[:date] }
         date = expected_holding[:date]
-        expected_price = expected_holding[:price]
+        expected_price = expected_holding[:price].to_d
         expected_qty = expected_holding[:qty]
-        expected_amount = expected_holding[:amount]
+        expected_amount = expected_holding[:amount].to_d
+        expected_currency = expected_holding[:currency]
         ticker = expected_holding[:ticker]
 
         assert actual_holding, "expected #{ticker} holding on date: #{date}"
-        assert_equal expected_holding[:qty], actual_holding.qty, "expected #{expected_qty} qty for holding #{ticker} on date: #{date}"
-        assert_equal expected_holding[:amount].to_d, actual_holding.amount.to_d, "expected #{expected_amount} amount for holding #{ticker} on date: #{date}"
-        assert_equal expected_holding[:price].to_d, actual_holding.price.to_d, "expected #{expected_price} price for holding #{ticker} on date: #{date}"
+        assert_equal expected_qty, actual_holding.qty, "expected #{expected_qty} qty for holding #{ticker} on date: #{date}"
+        assert_equal expected_amount, actual_holding.amount.to_d, "expected #{expected_amount} amount for holding #{ticker} on date: #{date}"
+        assert_equal expected_price, actual_holding.price.to_d, "expected #{expected_price} price for holding #{ticker} on date: #{date}"
+        assert_equal expected_currency, actual_holding.currency, "expected #{expected_currency} price for holding #{ticker} on date: #{date}"
       end
     end
 
diff --git a/test/support/account/entries_test_helper.rb b/test/support/account/entries_test_helper.rb
index fb0356f429f..34fd6f56d55 100644
--- a/test/support/account/entries_test_helper.rb
+++ b/test/support/account/entries_test_helper.rb
@@ -28,20 +28,20 @@ def create_valuation(attributes = {})
     Account::Entry.create! entry_defaults.merge(attributes)
   end
 
-  def create_trade(security, account:, qty:, date:, price: nil)
+  def create_trade(security, account:, qty:, date:, currency: "USD", price: nil)
     trade_price = price || Security::Price.find_by!(ticker: security.ticker, date: date).price
 
     trade = Account::Trade.new \
       qty: qty,
       security: security,
       price:    trade_price,
-      currency: "USD"
+      currency: currency
 
     account.entries.create! \
       name: "Trade",
       date: date,
       amount: qty * trade_price,
-      currency: "USD",
+      currency: currency,
       entryable: trade
   end
 end