US natural gas was once a notoriously volatile product – and traders who made big bets on market swings could expect to reap either handsome fortunes or eye-watering losses. In the past few years, though, the boom in unconventional production has made life much more boring for traders. As a proliferation of cheap shale gas has lowered prices and dampened volatility, many market participants have suffered from a decline in trading revenues, while banks have also been hit by a lull in client