Any new debt issue offering a scrap of yield has met huge demand from investors in recent months. As money floods into fixed-income funds, asset managers cannot put it to work in illiquid secondary markets, leaving the primary market as their only liquidity window. Small investors complain of being unfairly squeezed out from new-issue allocations. Large investors grumble that all other buyers are inflating their orders. And the elephant in the room? Nervous banks sense that regulators are preparing to pounce on traditional allocation practices in debt capital markets.