Double aggregation of queryset in django - django

Question

I need perform what is essentially a double aggregation. First, I need to get the average for the same events from different sources per ticker. Next, I need to get the sum of different events per ticker.
I can't figure out how to do this using Django. I've tried:
query1 = queryset.values('ticker', 'event_id').annotate(value_usd=Avg('value_usd'), shares=Avg('shares'), days_to_trade=Avg('days_to_trade'), num_trades=Count('ticker'))
query2 = query1.values('ticker').annotate(value_usd=Sum('value_usd'), shares=Sum('shares'), days_to_trade=Sum('days_to_trade'), num_trades=Count('security'))
but I receive an error django.core.exceptions.FieldError: Cannot compute Sum('value_usd'): 'value_usd' is an aggregate.
My raw data looks like this:
[{
'ticker': 'ACVA-US',
'source': 'INTERNAL',
'event_id': 300,
'value_usd': 3000.0,
'shares': 300.0,
'days_to_trade': 3.0,
'num_trades': 1
},
{
'ticker': 'ACVA-US',
'source': 'INTERNAL',
'event_id': 200,
'value_usd': 2000.0,
'shares': 200.0,
'days_to_trade': 2.0,
'num_trades': 1
},
{
'ticker': 'ACVA-US',
'source': 'EXTERNAL',
'event_id': 200,
'value_usd': 1000.0,
'shares': 100.0,
'days_to_trade': 1.0,
'num_trades': 1
}]
I need to perform what is essentially a double-aggregation. First, I need to take the average of items with the same ticker+event, which would look like:
[{
'ticker': 'ACVA-US',
'event_id': 300,
'value_usd': 3000.0,
'shares': 300.0,
'days_to_trade': 3.0,
'num_trades': 1
},
{
'ticker': 'ACVA-US',
'event_id': 200,
'value_usd': 1500.0,
'shares': 150.0,
'days_to_trade': 1.5,
'num_trades': 2
}]
Next, I need to sum up items across tickers, which would look like:
[{
'ticker': 'ACVA-US',
'value_usd': 4500.0,
'shares': 450.0,
'days_to_trade': 4.5,
'num_trades': 3
}]
I was hoping to do this without having to create a db view that performs the first aggregation, but so far I can't figure it out. I need to perform this at the queryset level without dropping into raw SQL because a bunch of other filtering occurs before and after this. Any advice?