I didn’t think that’s what I was doing, Novella, but yes you are quite right. Slavery was a key pillar of many of the developed and developing world’s economies in the 200 years from the mid 17th to late 19th centuries, and so many many financial institutions of the time would have been involved in the trade, one way or another. Not just in Britain, either. Ships had to be financed, insured, traders funded to buy the slaves, industries funded to acquire them. Slaves for often used as collateral for trade loans too. It’s an extraordinary and horrifying history.
Most of these were family businesses at the time though, and most no longer exist. Some exist in legacy form in modern institutions, though.