U.S. retirement accounts are starting to open the door to altcoins, which could mean a wave of money no longer goes exclusively into Bitcoin. But don’t get too excited: the real hurdle for 401(k) plans isn’t adding tokens to the menu—it’s how employers report them, custody them, and handle volatility. For retirement money to enter the market, there first needs to be a risk-management system more reliable than an exchange’s customer support.