Barclays successfully issued its second contingent capital note in less than six months on Wednesday, a relatively rare instrument that forms part of a plan to boost its capital buffers.

Barclays issued a 10-year $1bn CoCo that is subject to a write-off if Barclays' common equity tier-one capital falls below 7%, paying bondholders a coupon of 7.75%. The bond is callable, meaning that Barclays can buy the bonds back in five year's time at par.