Future margin idea : 1) Future contract 6 month period have historical big dump, last 3 contract since CME begin. 2) Now is wave 4 contract , start at 30 Sept 2018 - End 28 March 2019. 3) Usually base on last data, Last dump will be at H-14 until H-3 before settlement date.
Base on oscilator stochastic We see almost overbought from TF 8H 4H 1H 1D stoch maybe testing 50 level, before drop I think BTC top between 440XX - 42xx