Inflation is like rain. It affects us all, it causes problems, and it can be a nightmare to deal with. But, if it went away entirely, we would miss it. With inflation worries resurfacing, investors are again being told they need shelter from any coming storm.

For decades, investors - particularly pension funds - have protected themselves against inflation simply by buying index-linked government bonds. However, in recent years they have been encouraged into the swaps market, first by investment banks, then by asset managers offering what has become known as liability-driven investment - cash funds with swap overlays.