Bitcoin is usually, but not always, a buy when it enters ab Historically, bitcoin entering a bear market has been great buying opportunity. But not always. Bitcoin (BTCUSD) was trading under $100,000 on Friday morning, well below its early October peak. MarketWatch looked at data since 2014 when bitcoin fell at least 20% from highs. {table} The median gain six months later has been 31% and the median gain 12 months later is 42%. But there also have been situations where even a year later, bitcoin is still down by some 70%. Bitcoin, of course, has no fundamental value, even with aggressive retail and increasingly ... (full story)