Being long bitcoin is the most crowded trade in the world, according to a fund manager survey conducted by Bank of America Merrill Lynch. The cryptocurrency has surged higher in recent weeks as a handful of exchanges have started transacting it, offering an increased level of legitimacy. The cryptocurrency’s value has increased roughly 1,800% versus the US dollar this year, growing its market cap to more than $300 billion, according to CoinMarketCap.com.