Symbiont, the smart contracts platform for institutional applications of the blockchain, has raised $21.5M in funding from investors that include Citi Ventures, Raptor Group, Galaxy Digital LP, and Nasdaq Ventures. Founded by Adam Krellenstein, Evan Wagner, Mark Smith, and Robby Dermody in 2013, Symbiont has now raised a total of $36.9M in funding over three funding rounds.