Sorry to tell you but the spread isn't meaningful because some brokerages will not/cannot operate in a spread less than 5 cents or a trade price not divisible by a nickel. Ameritrade is one but others choose as fits their choices. This is an example of rigged trading parameters. I dislike it but it is what it is. As an Ameritrade customer---if I were to place an order to buy NGL right now at $15.99---it'd be rejected!