This interacts with the efficient market hypothesis in an interesting way. Suppose a magic button test that would instantly and freely tell anyone if they would make money (in expectation) on the market. Its not omniscient, but it is epistemically efficient compared to humans. All hopefuls press the button, and only trade if they pass the test. Those that pass make money. That money is coming from the people who actually want to buy or sell stuff, and the stubbornest of those who failed the magic button test.
(Assuming that people don’t try to use this as a way to send info back in time, or otherwise munchkin it.)
This interacts with the efficient market hypothesis in an interesting way. Suppose a magic button test that would instantly and freely tell anyone if they would make money (in expectation) on the market. Its not omniscient, but it is epistemically efficient compared to humans. All hopefuls press the button, and only trade if they pass the test. Those that pass make money. That money is coming from the people who actually want to buy or sell stuff, and the stubbornest of those who failed the magic button test.
(Assuming that people don’t try to use this as a way to send info back in time, or otherwise munchkin it.)