Japan's biggest banks have navigated through a year of negative interest rates and choppy financial markets with their profits intact, thanks at least in part to Donald Trump.

When the Bank of Japan announced the policy on Jan. 29 last year, shareholders, analysts and executives gave it a firm thumbs down. Lenders' shares tumbled in the ensuing months as investors deduced that the BOJ's move would squeeze already-depressed interest income and do little to spur credit demand.

A year later, Mitsubishi UFJ Financial Group Inc., Sumitomo Mitsui Financial Group Inc. and Mizuho Financial Group Inc. are on course to exceed their fiscal-year profit goals, having all beaten analysts' estimates for third-quarter earnings. Surging global bond yields and market volatility since Trump's November election victory have been a boon to the banks' fixed-income trading, helping to offset weak lending profitability, the results show.