diff --git a/app/Interfaces/MarketData/AlphaVantageMarketData.php b/app/Interfaces/MarketData/AlphaVantageMarketData.php
index 355742c..e1347dd 100644
--- a/app/Interfaces/MarketData/AlphaVantageMarketData.php
+++ b/app/Interfaces/MarketData/AlphaVantageMarketData.php
@@ -98,13 +98,15 @@ class AlphaVantageMarketData implements MarketDataInterface
 
                         return Carbon::parse($date)->between($startDate, $endDate);
                     })
-                    ->map(function($history, $date) use ($symbol) {
+                    ->mapWithKeys(function($history, $date) use ($symbol) {
+
+                        $date = Carbon::parse($date)->format('Y-m-d');
                         
-                        return [ 
-                            'symbol' => $symbol,
-                            'date' => Carbon::parse($date)->format('Y-m-d'),
-                            'close' => (float) Arr::get($history, '4. close')
-                        ];
+                        return [ $date => [
+                                'symbol' => $symbol,
+                                'date' => $date,
+                                'close' => (float) Arr::get($history, '4. close')
+                            ]];
                     });
     }
 }
\ No newline at end of file
diff --git a/app/Interfaces/MarketData/FakeMarketData.php b/app/Interfaces/MarketData/FakeMarketData.php
index 9a3cfd4..e99bb62 100644
--- a/app/Interfaces/MarketData/FakeMarketData.php
+++ b/app/Interfaces/MarketData/FakeMarketData.php
@@ -2,6 +2,7 @@
 
 namespace App\Interfaces\MarketData;
 
+use Illuminate\Support\Carbon;
 use Illuminate\Support\Collection;
 
 class FakeMarketData implements MarketDataInterface
@@ -66,13 +67,16 @@ class FakeMarketData implements MarketDataInterface
 
     public function history($symbol, $startDate, $endDate): Collection
     {
+        $numDays = Carbon::parse($startDate)->diffInDays($endDate, true);
 
-        for ($i = 0; $i < 14; $i++) { 
+        for ($i = 0; $i < $numDays; $i++) { 
 
-            $series[] = [
+            $date = now()->subDays($i)->format('Y-m-d');
+
+            $series[$date] = [
                 'symbol' => $symbol,
-                'date' => now()->subDays($i)->format('Y-m-d'),
-                'close' => (float) rand(1, 100),
+                'date' => $date,
+                'close' => (float) rand(150, 400),
             ];
         }
         
diff --git a/app/Interfaces/MarketData/YahooMarketData.php b/app/Interfaces/MarketData/YahooMarketData.php
index ebbc217..77c8773 100644
--- a/app/Interfaces/MarketData/YahooMarketData.php
+++ b/app/Interfaces/MarketData/YahooMarketData.php
@@ -77,13 +77,15 @@ class YahooMarketData implements MarketDataInterface
     {
 
         return collect($this->client->getHistoricalQuoteData($symbol, ApiClient::INTERVAL_1_DAY, $startDate, $endDate))
-            ->map(function($history) use ($symbol) {
+            ->mapWithKeys(function($history) use ($symbol) {
 
-                return [
-                    'symbol' => $symbol,
-                    'date' => $history->getDate()->format('Y-m-d'),
-                    'close' => (float) $history->getClose(),
-                ];
+                $date = $history->getDate()->format('Y-m-d');
+
+                return [ $date => [
+                        'symbol' => $symbol,
+                        'date' => $date,
+                        'close' => (float) $history->getClose(),
+                    ]];
             });
     }
 }
\ No newline at end of file