Robinhood and Coinbase are racing to own prediction markets, but Robinhood’s early start is paying off, with shares up more than 200% this year while Coinbase lags. With both firms using acquisitions to scale and regulators recently taking a friendlier stance, the competition now comes down to who can deliver deeper liquidity, cleaner settlement and scale faster, CNBC's Mackenzie Sigalos reports. Watch more: cnb.cx/4pnRWYH | CNBC