The first six months of 2020 proved to be something of a game of two halves for UBS Wealth Management, as strong performance in the first quarter gave way to lower fee income and credit losses in the second.

The result also highlights the extent to which wealth managers – so far looking resilient in the face of the Covid-19 pandemic – may become vulnerable in the coming months as the volatility-driven trading boom dies down.

In the second quarter, UBS Wealth...