He called Bitcoin a "Pioneer with arrows in it's back" today while a guest on CNBC's "Fast Money" - it's an opinion that's becoming more popular over time, which basically says Bitcoin will go down as the coin that simply paved the way for another newer coin to eventually dominate.So what coin does he think will take the #1 spot from Bitcoin? O'Leary believes Ethereum is "becoming the new platform" adding that if he was heavily invested in Bitcoin he'd be starting to worry now.O'Leary also touched on the topic of large investors, bankers and Wall Street types entering the market and bringing billions with them, but currently holding them back is "The regulators aren't on board yet, and we have to wait until that happens... then you'll see real money."That's something we've written about many times - traditional investors want regulators to make the rules clear before they start investing large sums of money into the cryptocurrency market. It's a topic the cryptocurrency community is divided on currently, with some saying the current 'wild west' atmosphere of lax regulations is why they got involved in the first place.Kevin O'Leary is a Canadian businessman, author and television personality. He co-founded O'Leary Funds and SoftKey.