Bitcoin holders stand to lose real BTC this weekend by trying to sell coins from a fork that may not even be worth anything. Both chains initially accept identical transactions — so a transaction signed to send the fork coins can also be broadcast on bitcoin. How selling a fork coin can cost a holder real bitcoin. (Shaurya Malwa/CoinDesk)A replay does not drain the wallet. Only the coins put up for sale move, and they leave as real bitcoin rather than the fork version, with a transaction fee paid on both chains.