Wells Fargo WFC.N led declines among big banks with a 1.1% fall. Unemployment rate dropped to its pre-pandemic low of 3.5% in April, the report is also likely to show, while wages rose solidly, underscoring the challenge the Federal Reserve faces to curb high inflation. The main indexes plunged on Thursday, reversing all gains from a relief rally on Wednesday, as investors feared bigger rate hikes might be needed to tame inflation running at a four-decade high.