Bitcoin, the world's most prominent digital currency, has produced more robust risk-adjusted returns over the last year than rival gold or the benchmark S&P 500 index, according to data provided by market research firm TradeBlock. To arrive at this conclusion, TradeBlock leveraged the Sortino Ratio, which is similar to the Sharpe Ratio but penalizes only downside volatility when calculating risk-adjusted returns. The Sortino Ratio measures an asset's gains, relative to the upside volatility that it experiences. TradeBlock looked at risk-adjusted returns since some assets generate very compelling returns, but also ... (full story)