Greed Inc. is an interesting take on a loose stock market, except that its stock market is far more about insider trading and corporate fraud. Really, it's market isn't driven by non-player forces; but that the players as corporate shysters having all the control over the prices is kind of premise here. It does buyouts in a funny way in that the goal is to actually have your CEOs get fired and take as much 'severance pay' as possible to by assets (the only thing that determine victory).
I can't recommend it as an alternative take on stock markets as much as recommending Greed Inc. as a making a source material that rationalizes an 18XX-like stock market.
I admire Splotter's stuff. Both 'Roads & Boats' and 'Antiquity' are brilliant. I just may have to check this out.