Django rest . Как объединить ответы в один

Сейчас у меня такой ответ.

    {
    "symbol": "ZERO",
    "costs": "6.1391",
    "timestamp": "2020-04-08T14:15:55.765835Z"
},
{
    "symbol": "ZERO",
    "costs": "6.1892",
    "timestamp": "2020-04-08T14:15:01.775659Z"
},
{
    "symbol": "ZERO",
    "costs": "6.1221",
    "timestamp": "2020-04-08T14:13:49.217715Z"
},

А нужен такой

{"symbol":"ZERO","costs":[
{"timestamp":"2019-12-14T00:00:07+00:00", "price":5.9505181}, 
{"timestamp":"2019-13-14T00:00:07+00:00", "price":5.915181}, 
{"timestamp":"2019-14-14T00:00:07+00:00", "price":6.915181}
]}

serializers.py

class CoinCostsSerializer(serializers.ModelSerializer):
    symbol = serializers.ReadOnlyField(source='coin_id.symbol')
    costs = serializers.CharField(source='price')
    class Meta:
        fields = ('symbol', 'costs', 'timestamp')
        model = CoinCosts

views.py

class CoinCostFilterSet(filters.FilterSet):

    class Meta:
        model = CoinCosts
        fields = {
            'coin_id__symbol': ['exact'],
            'timestamp': ['gt', 'lt'],
        }


class CoinCostViewSet(viewsets.ModelViewSet):

    queryset = CoinCosts.objects.all()
    serializer_class = CoinCostsSerializer
    filter_backends = (filters.DjangoFilterBackend,)
    filterset_class = CoinCostFilterSet

Как мне добиться такого ответа? Спасибо