Recommended contract: XBT7D (Bitmex weekly BTC/USD futures contract)
BUY LONG XBT7D (BitMEX weekly BTC/USD futures contract) while OKCoin.com spot is at 240-238 USD with a spot stop limit of 236 USD.
Close XBT7D long position at 255-260 USD;
Consider reducing the position by 40%-60% by taking profit at 250 USD.
A recent break of the inner uptrend line indicates a larger retracement coming soon. Wait for a reversal before going long at around 236 USD.