Well there is little doubt that many of the exchanges get "jammed up" during periods of high volatility in price. Until that problem is solved it is my opinion that trading bitcoin (and all other cryto prices will likely follow the fortunes/misfortunes of bitcoin) via the U.S. exchange traded "bitcoin tracking" device that is GBTC is the way to go becuz then at least you know you can get your money out within a few seconds of executing your sell order. And right now GBTC is definitely saying ythat you should be exiting you bitcoin holdings and banking gains.

http://bigcharts.marketwatch.com/advchart/frames/frames.asp?show=&insttype=&symb=gbtc&x=46&y=12&time=3&startdate=1%2F4%2F1999&enddate=2%2F18%2F2017&freq=7&compidx=aaaaa%3A0&comptemptext=&comp=none&ma=0&maval=9&uf=0&lf=1024&lf2=2&lf3=8&type=2&style=320&size=4&timeFrameToggle=false&compareToToggle=false&indicatorsToggle=false&chartStyleToggle=false&state=9