I personally feel that lvl 2 data is not useful for a retail Investor but my opinion of what a retail investor differs from others. to me a retail investor is someone who really just is trying to buy and hold some stocks usually don't know much about the market or charting or how to use Indicators.  then there's a breaking retail investor which is someone who could benefit from lvl 2 datat trying to break into the Investing world, learning a little more on when to get in and out ...