bitshares has been upgraded to bitshares 2.0 on 2015 together with the introduction of several new features.  it's one of the first so-called 2nd generation blockchain to be developed.  ethereum is also a 2nd gen blockchain.  bitcoin is 1st gen blockchain.  eos, meanwhile, is a 3rd gen blockchain.  upon introduction of bitshares 2.0, hardfork happened on the blockchain and bts v1 holders are required to claim their bts v2 coins.