The American consumer is sending Wall Street two very different messages.

One message comes from surveys.

It is increasingly pessimistic.

The other comes from actual behavior.

It is still spending.

That split is becoming one of the most important economic stories of the fourth quarter. Consumer confidence fell to 81.9 in September, the lowest reading since 2014, while inflation expectations rose and households became more concerned about jobs, gasoline prices and the broader economy. Yet consumer spending remained remarkably resilient, with personal consumption expenditures rising 0.9% in August, while second-quarter GDP was recently revised higher to a 2.2% annualized pace on stronger consumer spending and business investment.

That contradiction is exactly why investors have so much to watch this week.

The question isn't simply whether Americans feel bad about the economy.

It is whether that pessimism is finally turning into weaker spending.

The Conference Board's September reading was not a small decline.

The index dropped 6.7 points from August's 88.6 to 81.9, while the Expectations Index fell to 63.6. Consumers became more pessimistic about business conditions, employment and their own financial outlook. The survey also showed more people saying jobs were harder to find, while mentions of prices, gasoline and oil reached unusually high levels.

That matters because confidence is one of the earliest signals economists watch for a change in consumer behavior.

People generally don't slash spending the moment sentiment falls.

There is often a delay.

A household might complain about inflation for months while continuing to pay for groceries, utilities, travel or a needed vehicle repair. But if pessimism persists long enough, discretionary purchases can eventually be postponed.

That is the risk investors are watching now.

The strange part is that the spending numbers have not yet confirmed the pessimism.

The Commerce Department's latest data showed personal consumption expenditures rose 0.9% in August, while inflation-adjusted consumer spending also remained positive. The government's revised second-quarter GDP estimate showed consumer spending growing at a 3.8% annual rate, stronger than previously reported.

Because household consumption represents more than two-thirds of U.S. economic activity, that resilience is enormously important.

It explains how the economy can maintain solid growth even while confidence surveys deteriorate.

Americans can be unhappy and still spend.

In fact, some of the strongest spending may be coming from households that have enough income and wealth to keep consuming despite higher prices.

That creates a two-speed consumer economy.

The U.S. consumer is not one homogeneous group.

Households with substantial exposure to equities and real estate have benefited from large gains in asset values. That can cushion the effect of higher prices and borrowing costs.

Other households are in a much more difficult position.

They have less savings.

They are more exposed to food and transportation costs.

They may have less flexibility when mortgage rates, rent, insurance and gasoline all rise at the same time.

The result is an economy in which aggregate spending can remain strong even while a large portion of the population feels increasingly stressed.

That helps explain why consumer sentiment can reach levels normally associated with much weaker economic conditions while retail demand remains surprisingly durable.

The timing of the confidence slump is particularly important.

Oil prices have surged as the Iran conflict continues to disrupt the global energy system, with Brent crude recently moving above $100 a barrel. Diesel and refined fuel prices have come under especially heavy pressure.

Consumers see the effects immediately.

Gasoline is highly visible.

Transportation costs feed into food prices.

Higher freight costs can eventually show up in everything from packaged goods to services.

The Conference Board's September survey found that spontaneous mentions of oil and gasoline hit record levels, while one-year inflation expectations increased to 6.1%.

That creates a dangerous psychological feedback loop.

Consumers see higher prices.

They expect even higher prices.

They become more pessimistic.

Businesses may then face pressure to raise prices again.

The latest labor data also provide a reason for households to be cautious.

The September employment report showed payrolls increasing by only 29,000, far below economists' expectations, while the unemployment rate edged up to 4.2%. August payroll growth was revised lower as well.

The report did not show mass layoffs.

That is important.

But it did reinforce the idea that hiring has cooled significantly.

For workers, a low-layoff environment can still feel uncomfortable if employers are not hiring aggressively.

Someone with a job may feel secure enough to keep spending.

Someone trying to find a better job may decide to hold onto cash instead.

That is another reason the consumer could weaken gradually rather than collapse suddenly.

The economic calendar is unusually useful because several releases can test different parts of the consumer story.

Monday brings the ISM Services PMI, a critical gauge because services account for such a large share of the U.S. economy. The September reading should provide a fresh look at whether businesses are still seeing healthy demand.

Tuesday brings consumer credit data for August, offering clues about how much households are relying on borrowing to maintain spending.

Wednesday brings the minutes from the Federal Reserve's September meeting. Those minutes matter because investors will be looking for clues about how officials are balancing inflation risks against a softer labor market.

Thursday brings weekly jobless claims and the preliminary October University of Michigan consumer-sentiment reading. That last report could be especially important because it arrives after the September confidence plunge and the weak payroll report.

In other words, the week gives investors several different ways to determine whether pessimism is becoming behavior.

There is another reason Tuesday's consumer-credit figures matter.

If households continue spending while confidence falls, some of that spending may increasingly depend on credit.

That is sustainable only if income and employment can support the debt.

If credit-card balances and other household borrowing expand while wage growth slows and hiring weakens, the consumer could eventually hit a wall.

The problem would not necessarily appear as a sudden recession.

It could appear as a gradual reduction in discretionary spending.

Fewer restaurant visits.

Delayed vacations.

Cheaper electronics.

Less apparel spending.

More discount shopping.

Those incremental decisions can become significant when multiplied across hundreds of millions of consumers.

The Federal Reserve now faces an awkward combination.

The labor market is softer.

Consumer confidence is weak.

But inflation remains well above the central bank's long-run 2% goal.

The August PCE report showed headline inflation at 3.4% year over year, while core PCE was 3.0%. At the same time, the Fed has already raised rates and remains concerned about energy-driven price pressures.

That means policymakers cannot simply respond to weak sentiment by assuming they can rapidly ease policy.

If oil remains elevated, inflation could prove sticky.

If household spending remains strong, demand may not cool enough to remove that pressure.

And if hiring slows further, the Fed faces the opposite risk of waiting too long.

The contradiction is becoming the central policy problem.

For investors, the consumer story matters because corporate earnings ultimately depend on demand.

Retailers need shoppers.

Airlines need passengers.

Restaurants need customers.

Banks need borrowers who can repay their loans.

Technology companies need businesses willing to keep spending.

The current market can tolerate weak confidence if actual spending remains healthy.

It becomes much more vulnerable if spending starts matching the surveys.

That is why investors may be looking past the headlines and toward high-frequency data.

The key signal this week may be whether consumers are still behaving like the optimistic economy suggested by spending figures—or beginning to behave like the pessimistic economy described by surveys.

For now, the evidence points to resilience under pressure rather than outright collapse.

Household spending is holding up.

GDP growth has been revised higher.

Hiring has slowed, but layoffs remain relatively contained.

At the same time, confidence has fallen dramatically, inflation expectations are rising and higher energy costs are creating a fresh burden.

That makes the next phase unusually difficult to predict.

The American consumer may simply be complaining while continuing to spend.

Or the surveys may be an early warning of what comes next.

The distinction matters enormously.

Because once confidence finally turns into caution at the checkout counter, the economy can lose one of its most important sources of momentum surprisingly quickly.

This week won't answer every question.

But it could provide the first real clues about whether America's consumer pessimism is merely a mood—or the beginning of a spending slowdown.