I'm also talking about day-trading here. A retail investor might find worth in being a market maker for a few things which each have a daily volume of $25,000 a

I'm also talking about day-trading here. A retail investor might find worth in being a market maker for a few things which each have a daily volume of $25,000 and 1% margins. An institutional investor may see that $25,000 volume as a rounding error.