As 2015 drew to a close, corporate treasurers from 20 Fortune 500 companies gathered to discuss their respective hedging strategies.

"How many of you are outside your fixed rate tolerances?" Amol Dhargalkar, head of the global corporate sector practice at Chatham Financial, asked the group. All raised their hands. "So how many of you are going to floating?" Not one reached for the sky.

Corporate hedgers – it seemed – were going on strike.

Since last September, a collapse in the swap spread – the