The real risks - unemployment, foreclosure, environmental, social and political damage - are only carried by investors if they overwhelm the defensive perimeter created by wealth. Otherwise they're carried by everyone else.
Corporations may already a form of transcarnate lifeform. You can replace all of the humans in a corporation with a different set of humans, and the corporation will continue to be recognisable.
There's a bias in Darwinism to seeing species as embodied units. It's more useful to think of nutrient, resource, and information flows.
From that point of view, corporations are already apex predators - albeit ones that are still mostly passed between a selected class of humans as productive pets.
Giving them autonomy could have all kinds of unfortunate consequences.
Not really. Companies are typically limited liability, and even criminal law in countries such as the US and England acknowledges that there are cases when no particular human is culpable for a company's criminal actions (https://en.wikipedia.org/wiki/Corporate_liability). Of course, people are still liable when they are simply using a company to carry out a criminal enterprise, or wilfully committing crimes on behalf of the company.
In this regard, a machine-led company would not be legally significantly different from a human analyst-led company.
I'd say that it's a good thing that the law is generally not designed to punish harmful ends, but intent (wilful, negligent or reckless) to cause well-defined harmful ends. The financial crisis was a collective malfunction of the financial system that was mostly not anticipated (barring the lucky minority that bet against the status quo).
What if you can invent new methods of "reckless driving" before they are put in the legal system and thus reap their benefits?
It's just like designer drugs.
I think an important distinction is that drug prohibition often works in terms of specific chemicals by statute. E.g. drug X is now illegal for use and distribution.
Securities fraud law instead works in concepts and intentions and is fleshed out by case law. E.g. did the seller give the buyer sufficient information for the buyer not to have been defrauded?
A better analogy to securities using chemicals would be poisoning. The law doesn't need to catch up to specific chemicals; if it's evident that you wilfully, or recklessly added a poison to someone's food, it's illegal, and it doesn't matter how you did it. If it turns out that some ingredient is unknowingly toxic and the whole industry was adding it, then it's difficult to argue criminal intent. The SEC is more like the FDA, than it is the DEA.
There are investment funds that work as hybrids, and of course it's just a matter of time till someone offers shell-company-as-a-service for cheap. (Currently it's rather pricey.)