What do you guys think some of the advantages are for both institutional and retail traders? Here's my two cents: Institutional - 1. Technology. ex. Renaissance supercomputers 2. Order flow. ex. MMs doing conversions and reversals. 3. Portfolio margin. Less collateral needed for hedges; M&A arbitrage; etc. Retail - 1. Low, fixed commissions. 2. Liquidity. Trading any security one wants and getting filled at the exact price. Feel free to add more to the list.