One potential target audience might be employees / executives of publicly traded companies. If Alice owns stock in her employer or her employers' partners / suppliers / clients, she may be very interested in an algorithmic position manager to help her achieve her financial goals (e.g. selling down if the position exceeds a certain percentage of her net worth).
The main reason Alice would like this is to create an audit trail that defends her against any hypothetical insider trading accusations. That is, your brokerage will have records that explain not only what trades occurred (as any brokerage will do), but also why those trades occurred (you ran algorithm F on X input and F(X) is what popped out).
Next step: bespoke algorithms with neural nets trained just so to produce the result you want. “We’re about to close this deal, run the algorithm that decides to buy $vendor stock”
Setting an algorithm loose on the stocks that you own in your employer is not a great look from a compliance perspective at all. And if you give it specific instructions like try to sell down my holdings optimally, that doesn't relieve you of insider trading allegations at all. If you want to sell, follow the appropriate compliance procedure, then you're free to do so in whichever way you like.
First, some publicly traded companies have freezes and employees can only trade in specific windows. The algorithm will need to take this into account.
Second, is "an algorithm did so" a legitimate defense ? It will probably depend on the jurisdiction but i can imagine lots of courts dismissing that because regardless of algorithms, it's on the human not to act illegally, and humans have created, tuned and parametered said algo. I don't think laws have been updated for such cases ( like with self-driving cars).
This doesn’t work if you have the ability to let good trades proceed but cancel bad trades after having learned nonpublic info. You’d have to commit to a https://www.investopedia.com/terms/r/rule-10b5-1.asp plan during an open trading window, and I don’t know how complex the price/quantity formula is allowed to be.
The main reason Alice would like this is to create an audit trail that defends her against any hypothetical insider trading accusations. That is, your brokerage will have records that explain not only what trades occurred (as any brokerage will do), but also why those trades occurred (you ran algorithm F on X input and F(X) is what popped out).