Wall Street is bracing for the 105-minute thrill ride of the summer. I refer not to the latest Hollywood blockbuster but to Thursday’s interest-rate decision by the US Federal Reserve.

The fact that the Fed’s decision coincides with the end of the second quarter could lead to volatility, particularly in strong sectors like energy and laggards in the tech and auto industries. US money managers have less than two hours to react and make their portfolios presentable.