One of the options market’s closely watched indicators is starting to show that speculators are getting nervous ahead of a once-every-four-years Bitcoin code adjustment that has been bullish for the cryptocurrency in the past. The implied volatility for Bitcoin options jumped last weekend, reversing a downward trend seen in the prior week, Kaiko Research said in a report. An increase generally means market participants are less confident about the direction of prices, said Adam McCarthy, a research analyst at Kaiko. When implied volatility rises, traders are usually willing to pay more to protect existing positions ... (full story)