(Bloomberg) -- The race-to-the-bottom on fees among prospective spot Bitcoin ETF issuers picked up speed with at least four companies slashing their costs.Most Read from BloombergIPhone Survives 16,000-Foot Fall, Helps Steer Jet-Panel HuntChinese Billionaire Is Second-Biggest Foreign Owner of US LandUS and Allies Met Secretly With Ukraine on Peace PlanXi, Biden and the $10 Trillion Cost of War Over TaiwanStocks Waver After Tech-Led Bounce; Oil Rebounds: Markets WrapInvesco, Bitwise, Valkyrie and