Django Rest Framework bulk updates inserting instead of updating

Just in case somebody is looking for a library to handle this, I wrote a Django-REST-Framework-bulk which allows to do that in a couple of lines (the example only does bulk update but the library also allows bulk create and delete):

from rest_framework_bulk import ListCreateBulkUpdateAPIView

class FooView(ListCreateBulkUpdateAPIView):
    model = FooModel

You're not passing object instances to your serializer. (Thus it will create new instances rather than update.) See the docs on dealing with multiple objects in serializers where you'll see your QuerySet passed in.