Last year marked the worst period for London IPOs since the financial crisis. But for the banks that earn fees advising on them, another equity product proved lucrative: share buybacks.

Buybacks are big business — and getting bigger. Last year, FTSE 100 firms committed to at least £57bn worth of buybacks, according to investment platform AJ Bell. That was the third straight year above £50bn, and FTSE 100 firms have already laid out plans to return more than £17bn through buybacks this year.