Between the time I shot this video and now Bitfinex has got rid of almost all of its US customers due to SEC problems with ICO's. It's a huge shame too because they had probably the best interface and exchange in my opinion. They had a ticker that would show the USD amount you would receive for market selling all your shares, and it would live update to the price making it super easy to cash out at the right time.

Along with the feature I just mentioned they also have trailing stop orders. If you don't know what a trailing stop is, it's a type of order that follows your profit by a certain margin and market sales your shares if the price starts to drop, however it moves itself based on how the price is trending. Watch my video to find out more.