Nothing is certain these days! The ZKB and other AAA rated cantonal banks are relatively the safest. At least the taxpayers enjoy(ed) the profits.

The US model appears to be: Profits for the capitalists and losses for the state! That defrauds the taxpayers.

Hence, I am convinced that ZKB (also any other AAA rated Swiss cantonal banks) and the Swiss Government's PostFinance are the only safe(r) choices.