In an investment bank a trader has a high ratio of support staff around them: legal, compliance, IT, operations, quants, finance/tax, risk. These 'support' job

In an investment bank a trader has a high ratio of support staff around them: legal, compliance, IT, operations, quants, finance/tax, risk. These 'support' jobs are a significant fraction of the real cost of a trading seat - not just the trader's salary. Automation has happened incrementally in the industry for years, like many others - starting with the easiest stuff (low hanging fruit) like some operations tasks and mechanical trading tasks, and leaving the more complex tasks for humans - or letting a human scale to do more. The more complex tasks that are left typically require non-trivial intelligence, e.g. understanding why the new product brought to market by your competitor or counterparty is slightly different to what you are trading today, and deciding if you can/should transact in it. Understanding what impact the upcoming compliance rule changes have on your market and activities (there are always regulatory rule changes). Understanding what the limits of your trading are, to avoid concentrating too much exposure in one area. Understanding why your counterparty is upset about some aspect of the transaction. etc.