Having taken a gamble on bitcoin futures, which are set to begin trading by the end of the year, the CME is now seeking to avoid the consequences of what has emerged as both the cryptocurrency's best and worst selling point: its unprecedented volatility. To do that, the Chicago-based exchange will do what it does to virtually every other asset class traded under its roof, and impose limits on how much prices of bitcoin futures can fluctuate within a day.

While the CME already uses daily vol limits on most other markets, including crude, gold and market futures, to temporarily halt trading when price swings get out of control, the CME has never before dealt with something like bitcoin, which in addition to being the world's best performing asset classes in recent years, is also its most volatile. And, as the WSJ adds, it is also unclear how much impact CME’s limits will have on bitcoin, since its futures market has yet to emerge and most trading in the digital currency is on exchanges outside of CME’s control.

In any case, based on the CME's preliminary term sheet, bitcoin trading limits would kick in when the price of its bitcoin futures move 7%, 13% or 20% up or down from the previous day’s closing price. The first two thresholds, for 7% and 13% moves, are “soft” limits, which would trigger a two-minute pause in trading of bitcoin futures. The 20% limit would be a “hard” stop on how far CME’s bitcoin futures could swing on any day.

By comparison, the CME has similar staggered volatility control on its popular E-mini S&P 500 futures contract, which also has three successive price-fluctuation limits at 7%, 13% and 20% during regular trading hours. A nighttime limit of 5% was hit in the S&P 500 futures on Nov. 8, 2016, when news of Donald Trump’s upset win in the U.S. presidential election triggered wild volatility in stock-market futures, only for the S&P to surge 21% in the 12 months since.

Of course, bitcoin will be a far "wilder" and more volatile instrument than the S&P 500 (one hopes). According to Coindesk calculations, so far in 2017 there have been two days in which bitcoin’s price swung more than 20% in a single day. There were 11 days in which it moved at least 13%, and 69 in which it moved at least 7%.

The full bitcoin contract specsheet is below.