This would requires support for a bucket script in Kibana data-tables, which there is not now https://github.com/elastic/kibana/issues/4707
You could run this query manually too in dev-tools.
This would be an example of how to do it:
- top-level term-aggregation on
tradeReference
- min sub aggregation to get minimum date
- max sub-aggregation to get maximum date
- bucket sub-aggregation to subtract max from min