According to @Andre_Dragosch, the reported probability of negative BTC returns declines with longer holding periods: 46.9% for 1 day, 44.3% for 1 week, 42.2% for 1 month, 36.5% for 1 quarter, 23.5% for 1 year, 0.7% for 3 years, 0.2% for 5 years, and 0% for 10 years, source: @Andre_Dragosch. The author concludes this favors a HODL approach as multi year horizons show near zero loss odds compared with short term windows, source: @Andre_Dragosch.