This week, Walmart and the Fed minutes put the consumer on trial

A new week begins, and what markets worry about is shifting. Until recently the fear was that inflation would flare up again; now it is that shoppers are closing their wallets. The S&P 500 hit a record last week, but Friday's retail sales report, which fell when a small rise was expected, took some of the shine off. Consumer sentiment also dropped for the first time in three months, and 4.7% of household debt is delinquent.

This week's earnings should show whether the worry is real. With few economic reports on the calendar, Walmart, Target and Home Depot become the stand-ins for the health of the American consumer. Some argue the retail sales dip was mostly down to Amazon moving its sale from July to June, so what these big retailers say will matter.

On rates, the Fed releases minutes from its July meeting. Three officials dissented in favor of raising rates, and the minutes should show what the argument looked like. It may sound odd, but the debate at the Fed is no longer about when to cut; it is about whether to hike. A newer wrinkle, that computers and phones have stopped getting cheaper, is likely to come up too.

It is also worth noting how quiet the market is. The volatility index sits near multiyear lows and few investors are buying protection. Some analysts think that calm could break once this week's options expiration passes.