I am mapping the geolocated location information for 5.5k Twitter profiles as point data. Many of them have the same location ie "London, UK" meaning that they return identical coordinates. On the map these overlaid features appear the same as a single feature, meaning density is hidden.

I would like to create a symbol style that aggregates all the features with the same co-ordindates as a single symbol sized according to how many features are located there. Can anyone help with this?

Multiple overlaid features, next to a single feature, look the same