diff --git a/app/Models/Holding.php b/app/Models/Holding.php
index 5e94787..0fba5bc 100644
--- a/app/Models/Holding.php
+++ b/app/Models/Holding.php
@@ -30,6 +30,7 @@ class Holding extends Model
 
     protected $casts = [
         'splits_synced_at' => 'datetime',
+        'first_transaction_date' => 'datetime'
     ];
 
     protected $attributes = [
@@ -133,7 +134,7 @@ class Holding extends Model
 
     public function scopePortfolio($query, $portfolio)
     {
-        return $query->where('portfolio_id', $portfolio);
+        return $query->where('holdings.portfolio_id', $portfolio);
     }
 
     public function scopeSymbol($query, $symbol)
@@ -220,6 +221,49 @@ class Holding extends Model
 
         $this->save();
     }
-}
 
-    
\ No newline at end of file
+    public function dailyPerformance(
+        \Illuminate\Support\Carbon $start_date = null, 
+        \Illuminate\Support\Carbon $end_date = null, 
+    ) {
+        if ($start_date == null) $start_date = now();
+        if ($end_date == null) $end_date = now();
+
+        $date_interval = "DATE_ADD(date, INTERVAL 1 DAY)";
+
+        if (config('database.default') === 'sqlite') {
+            $date_interval = "date(date, '+1 day')";
+        }
+
+        return DB::table(DB::raw("(
+                WITH RECURSIVE date_series AS (
+                    SELECT '{$start_date->format('Y-m-d')}' AS date
+                    UNION ALL
+                    SELECT $date_interval
+                    FROM date_series
+                    WHERE date < '{$end_date->format('Y-m-d')}'
+                )
+                SELECT date_series.date
+                FROM date_series
+            ) as date_series")
+        )
+        ->select([
+            'date_series.date',
+            DB::raw("
+                COALESCE(SUM(CASE WHEN transactions.transaction_type = 'BUY' THEN transactions.quantity ELSE 0 END), 0) -
+                COALESCE(SUM(CASE WHEN transactions.transaction_type = 'SELL' THEN transactions.quantity ELSE 0 END), 0) AS `owned`
+            "),
+            DB::raw("COALESCE(SUM(CASE WHEN transaction_type = 'BUY' THEN (quantity * cost_basis) ELSE 0 END), 0) AS `cost_basis`"),
+            DB::raw("COALESCE(SUM(CASE WHEN transaction_type = 'SELL' THEN ((sale_price - cost_basis) * quantity) ELSE 0 END), 0) AS `realized_gains`")
+        ])
+        ->leftJoin('transactions', function ($join) {
+            $join->on(DB::raw('DATE(transactions.date)'), '<=', 'date_series.date')
+                ->where('transactions.symbol', '=', $this->symbol)
+                ->where('transactions.portfolio_id', '=', $this->portfolio_id);
+        })
+        ->groupBy('date_series.date')
+        ->orderBy('date_series.date')
+        ->get()
+        ->keyBy('date');
+    }
+}
\ No newline at end of file
diff --git a/app/Models/Portfolio.php b/app/Models/Portfolio.php
index 4ebcdee..fae8ed8 100644
--- a/app/Models/Portfolio.php
+++ b/app/Models/Portfolio.php
@@ -2,7 +2,10 @@
 
 namespace App\Models;
 
+use Illuminate\Support\Arr;
+use Illuminate\Support\Facades\DB;
 use Illuminate\Database\Eloquent\Model;
+use App\Interfaces\MarketData\MarketDataInterface;
 use Illuminate\Database\Eloquent\Concerns\HasUuids;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 
@@ -74,7 +77,8 @@ class Portfolio extends Model
         return $this->users()->firstWhere('owner', 1)?->id;
     }
 
-    public static function syncUsers(self $model) {
+    public static function syncUsers(self $model) 
+    {
         // make sure we don't remove owner access
         $user_id[$model->owner_id ?? auth()->user()->id] = ['owner' => true];
 
@@ -86,4 +90,68 @@ class Portfolio extends Model
         // save
         $model->users()->sync($user_id);
     }
+
+    public function syncDailyChanges(): void
+    {
+        $holdings = $this->holdings()
+                ->join('transactions', function($join) {
+                    $join->on('transactions.symbol', '=', 'holdings.symbol')
+                         ->where('transactions.portfolio_id', '=', $this->id); 
+                })
+                ->select('holdings.*', DB::raw('min(transactions.date) as first_transaction_date')) // get first transaction date
+                ->groupBy('holdings.symbol') 
+                ->get();
+        
+        $total_performance = [];
+
+        $holdings->each(function($holding) use (&$total_performance) {
+
+            $all_history = app(MarketDataInterface::class)->history('ACME', $holding->first_transaction_date, now());
+            $quantity = $holding->dailyPerformance($holding->first_transaction_date, now());
+
+            $dividends = $holding->dividends->keyBy(function ($dividend, $key) {
+                                        return $dividend['date']->format('Y-m-d');
+                                    })->toArray();
+
+            $dividends_earned = 0;
+            $daily_performance = [];
+
+            $all_history->sortBy('date')->each(function ($history, $date) use ($quantity, $dividends, &$daily_performance, &$dividends_earned) {
+
+                $close = Arr::get($history, 'close', 0);
+                $total_market_value = $quantity->get($date)->owned * $close;
+                $dividend = Arr::get($dividends, $date, []);
+                $dividends_earned += $quantity->get($date)->owned * Arr::get($dividend, 'dividend_amount', 0);
+
+                $daily_performance[$date] = [
+                    'date' => $date,
+                    'portfolio_id' => $this->id,
+                    'total_market_value' => $total_market_value, 
+                    'total_cost_basis' => $quantity->get($date)->cost_basis,
+                    'total_gain' => $total_market_value - $quantity->get($date)->cost_basis,
+                    'realized_gains' => $quantity->get($date)->realized_gains,
+                    'total_dividends_earned' => $dividends_earned
+                ];
+            });
+
+            foreach ($daily_performance as $date => $performance) {
+                if (!isset($total_performance[$date])) {
+                    
+                    $total_performance[$date] = $performance;
+
+                } else {
+                    
+                    $total_performance[$date]['total_market_value'] += $performance['total_market_value'];
+                    $total_performance[$date]['total_cost_basis'] += $performance['total_cost_basis'];
+                    $total_performance[$date]['total_gain'] += $performance['total_gain'];
+                    $total_performance[$date]['realized_gains'] += $performance['realized_gains'];
+                    $total_performance[$date]['total_dividends_earned'] += $performance['total_dividends_earned'];
+                }
+            }
+        });
+
+        $this->daily_change()->delete();
+
+        DailyChange::insert($total_performance);
+    }
 }
diff --git a/database/factories/TransactionFactory.php b/database/factories/TransactionFactory.php
index da972c0..7a5ea48 100644
--- a/database/factories/TransactionFactory.php
+++ b/database/factories/TransactionFactory.php
@@ -39,7 +39,14 @@ class TransactionFactory extends Factory
     public function yearsAgo(): static
     {
         return $this->state(fn (array $attributes) => [
-            'date' => $this->faker->date('Y-m-d', '-3 years'),
+            'date' => $this->faker->dateTimeBetween('-5 years', '-3 years')->format('Y-m-d'),
+        ]);
+    }
+
+    public function lastMonth(): static
+    {
+        return $this->state(fn (array $attributes) => [
+            'date' => now()->subMonth()->format('Y-m-d'),
         ]);
     }
 
diff --git a/tests/SyncDailyChangeTest.php b/tests/SyncDailyChangeTest.php
new file mode 100644
index 0000000..3379fc7
--- /dev/null
+++ b/tests/SyncDailyChangeTest.php
@@ -0,0 +1,119 @@
+<?php
+
+namespace Tests;
+
+use Tests\TestCase;
+use App\Models\User;
+use App\Models\Holding;
+use App\Models\Portfolio;
+use App\Models\DailyChange;
+use App\Models\Transaction;
+use Illuminate\Support\Facades\Artisan;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+
+class SyncDailyChangeTest extends TestCase
+{
+    use RefreshDatabase;
+
+    /**
+     */
+    public function test_can_sync_daily_change_history(): void
+    {
+        $this->actingAs($user = User::factory()->create());
+
+        $portfolio = Portfolio::factory()->create();
+
+        Transaction::factory(5)->buy()->yearsAgo()->portfolio($portfolio->id)->symbol('ACME')->create();
+        Transaction::factory()->sell()->lastMonth()->portfolio($portfolio->id)->symbol('ACME')->create();
+        Transaction::factory(5)->buy()->yearsAgo()->portfolio($portfolio->id)->symbol('AAPL')->create();
+        Transaction::factory(5)->buy()->yearsAgo()->portfolio($portfolio->id)->symbol('GOOG')->create();
+        Transaction::factory(5)->buy()->yearsAgo()->portfolio($portfolio->id)->symbol('FOO')->create();
+        Transaction::factory(5)->buy()->yearsAgo()->portfolio($portfolio->id)->symbol('BAR')->create();
+
+        $portfolio->syncDailyChanges();
+
+        $count_of_daily_changes = $portfolio->daily_change()->count('date');
+        $days_between_now_and_first_trans = (int) now()->diffInDays($portfolio->transactions()->min('date'), true) + 1;
+
+        $this->assertEquals($count_of_daily_changes, $days_between_now_and_first_trans);
+    }
+
+    /**
+     */
+    public function test_sales_are_captured_as_realized_gains(): void
+    {
+        $this->actingAs($user = User::factory()->create());
+
+        $portfolio = Portfolio::factory()->create();
+
+        Transaction::factory(5)->buy()->yearsAgo()->portfolio($portfolio->id)->symbol('ACME')->create();
+        $sale_transaction = Transaction::factory()->sell()->lastMonth()->portfolio($portfolio->id)->symbol('ACME')->create();
+        Transaction::factory(5)->buy()->yearsAgo()->portfolio($portfolio->id)->symbol('AAPL')->create();
+        Transaction::factory(5)->buy()->yearsAgo()->portfolio($portfolio->id)->symbol('GOOG')->create();
+        Transaction::factory(5)->buy()->yearsAgo()->portfolio($portfolio->id)->symbol('FOO')->create();
+        Transaction::factory(5)->buy()->yearsAgo()->portfolio($portfolio->id)->symbol('BAR')->create();
+
+        $portfolio->syncDailyChanges();
+
+        $daily_change = DailyChange::query()
+            ->portfolio($portfolio->id)
+            ->whereDate('date', $sale_transaction->date)
+            ->first();
+
+        $realized_gain = ($sale_transaction->sale_price - $sale_transaction->cost_basis) * $sale_transaction->quantity;
+
+        $this->assertEqualsWithDelta($daily_change->realized_gains, $realized_gain, 0.01);
+
+        $day_before = DailyChange::query()
+            ->portfolio($portfolio->id)
+            ->whereDate('date', $sale_transaction->date->subDays(1))
+            ->first();
+
+        $this->assertEquals($day_before->realized_gains, 0);
+
+        $day_after = DailyChange::query()
+            ->portfolio($portfolio->id)
+            ->whereDate('date', $sale_transaction->date->addDays(1))
+            ->first();
+
+        $this->assertEqualsWithDelta($day_after->realized_gains, $realized_gain, 0.01);
+    }
+
+    public function test_dividends_captured_in_daily_change_sync(): void
+    {
+        $this->actingAs($user = User::factory()->create());
+
+        $portfolio = Portfolio::factory()->create();
+
+        Transaction::factory(5)->buy()->yearsAgo()->portfolio($portfolio->id)->symbol('ACME')->create();
+
+        Artisan::call('refresh:dividend-data');
+
+        $portfolio->syncDailyChanges();
+
+        $holding = Holding::query()->portfolio($portfolio->id)->symbol('ACME')->first();
+        $dividends = $holding->dividends()->get()->sortBy('date');
+
+        $first_dividend_change = DailyChange::query()
+            ->portfolio($portfolio->id)
+            ->whereDate('date', $dividends->first()->date)
+            ->first();
+
+        $owned = $dividends->first()->purchased - $dividends->first()->sold;
+
+        $this->assertEqualsWithDelta($dividends->first()->dividend_amount * $owned, $first_dividend_change->total_dividends_earned, 0.01);
+
+        $last_dividend_change = DailyChange::query()
+            ->portfolio($portfolio->id)
+            ->whereDate('date', $dividends->last()->date)
+            ->first();
+
+        $total_dividends = $dividends->reduce(function (?float $carry, $dividend) {
+            return $carry + ($dividend['dividend_amount'] * ($dividend['purchased'] - $dividend['sold']));
+        });
+
+        $owned = $dividends->last()->purchased - $dividends->last()->sold;
+
+        $this->assertEqualsWithDelta($total_dividends, $last_dividend_change->total_dividends_earned, 0.01);
+    }
+}