To most readers here I think I’m right in saying that the [Markets in Financial Instruments Directive](http://en.wikipedia.org/wiki/MiFID “MiFID”") won’t mean much. It’s some new Europe-wide legislation designed to help regulate financial transactions.
Stop yawning. Please. Come back! This isn’t going to be completely dry and boring, honest.
So, anyway, one of its major elements is a concept called “best execution.” This isn’t a choice between a firing squad or a noose. The idea is that a trader has to be able to prove that they made the best deal, with the right people, at the best price. (On a serious note, I think this is a sensible idea, I’m just not convinced that regulation is the right way to achieve it.)