The American consumer has been carrying the U.S. economy as the current economic expansion continues. Personal spending has increased in each of the last six months and consumer confidence hit a reading of 135.8 in July—one of the three highest readings since 1999.

Even the banks that have reported earnings this week have seen more consistency from the consumer banking side than they have the commercial side or from investment banking. Goldman Sachs missed on its earnings estimate earlier this week with trading and investment banking bringing overall results down. I wrote an article earlier this month about how unpredictable and volatile the IPO market has been this year. Goldman specifically was hurt by its investment in Uber and in the WeWork debacle.

As much as the consumer has done to keep the economic expansion going, there have been signs that the consumer is starting to crack—at least to some degree. Retail sales from September were released on Wednesday and they showed a decline of 0.3%. That figure was below the consensus estimate of 0.3% and it was well below the 0.6% increase we saw in August. It was the first decline in retail sales since February. The two areas that were down the most were building materials and autos/parts.

Looking back a little farther, the consumer confidence reading for September was released on October 4. The overall reading dropped to 125.1 as the expectations and present situation aspects dropped rather sharply. I have written a number of articles on consumer confidence in the past and it isn’t the absolute levels that I worry about, it is when we see big declines in consumer confidence that we tend to see corrections in the market and slowdowns in the economy.

Housing starts for September were released on Thursday and like the retail sales numbers, the housing numbers were down. Analysts expected the annualized rate to come in at 1.306 million, but the actual figure was 1.256 million. The August reading was higher than expected at 1.386 million and analysts were expecting the numbers to drop from that high reading, but the figures came in even lower than expected.

Housing and autos are two areas that are especially interest rate sensitive and should be doing better as the Fed cuts rates and as the 10-year treasury rate has declined so sharply over the last year. The 10-year yield was above 3.2% last year and fell as low as 1.43 in September. The 10-year yield is a benchmark used by banks to set the rates for a number of loan products, specifically mortgage rates and auto loan rates to some degree.

I don’t think it is time to push the panic button just yet, but the consumer is starting to look tired. The employment picture has remained strong and that has certainly helped keep consumer spending levels up and it has certainly helped keep the consumer confidence readings elevated for quite some time now.

Unfortunately, the business side of the economy has not been keeping up with the consumer side. The second quarter GDP report showed that business investment fell during the quarter and it was the first time in over three years that there was a decline.

The advanced estimate for third quarter GDP results won’t be released until October 30, but the Atlanta Fed has a tracking tool that predicts the GDP results based on various indicators. After the ISM reports were released in early October, the GDPNow model revised its GDP estimated growth to only 1.8% for the third quarter. You can bet that business investment was likely down during the third quarter as well.

The consumer has done its part to keep the expansion going, but if the economy is going to continue growing, businesses are going to have to step up their spending.