Speed Trader Jumps Into Crypto Bets Opposed by Watchdog Flow Traders NV, an Amsterdam-based speed trader, is making markets in the first exchange-traded notes based on Bitcoin and Ether, according to Co-Chief Executive Officer Dennis Dijkstra. XBT Provider, an issuer of crypto ETNs listed in Sweden, said that the Dutch company has “dramatically increased” trading of its securities in the last few months.