Wall Street banks prepare for round-the-clock stock trading, reluctantly

Round-the-clock trading is fast approaching U.S. stock markets, but not all of Wall Street is embracing the move. Several of the largest U.S. banks are reluctant to push aggressively into enabling round-the-clock stock trading, even as equity markets are marching toward a broad rollout of nearly nonstop trading later next year and exchanges are preparing for action.