Basically, machine controlled businesses (“slyly self-aware financial instruments”) evolving to the point where their aptitude at understanding and manipulating economics eclipses anything a human can compete with.
It terrified me because there is efficiency incentive for the buying/selling of goods and services to be realtime and computer based. Not just stock markets but also e-comm, smart contracts, supplier-buyer platforms, on-demand services, financing etc. The traditional infrastructure blocks (discovery, quality control, payments, compliance etc) are rapidly disappearing.
There are some yet to be addressed, but they are not huge. For example a computer cannot incorporate a company. But it could easily interact via API to a human nominee who sets one up on their behalf. Companies are already non-human in intention but are a completely rational construct.
And it doesnt even have to be anywhere near ground level. Imagine a smart contract from a private equity firm that legally forces businesses to act in a specific way based on accountancy metrics. And a bunch of smart investor bots rapidly tracking the progress of these bot-led funds. How quickly would the system optimise and what would those optimisations look like to people on the ground?
Out of all the disaster situations with AI this one strikes me as so realistic because there is so much incentive to work towards it (as opposed to creating skynet, hal or the paperclip machine).