https://www.cnbc.com/2017/11/08/cmes-planned-bitcoin-futures-will-attempt-to-rein-in-big-price-swings.html >The world's largest futures exchange wants to guard against extreme volatility in its planned bitcoin futures product. >CME will implement special price fluctuation limits at 7 percent and 13 percent above or below the prior settlement price, and prevent trading outside the 20 percent range, according to details the exchange released Tuesday afternoon.