The nation’s biggest banks have all built up big enough buffers to weather a severe recession in decent shape, U.S. regulators said Thursday.

The Federal Reserve looked at how the country’s 33 largest banks would do in a recession with sustained high unemployment and negative interest rates. It found that the big banks would all suffer major losses — $526 billion in total.

Yet even with those losses, regulators said, all of the big banks would remain in relatively good financial health — and well above minimum regulatory requirements — as a result of the big cushions of shareholder money they have stockpiled in the last few years.

Nearly eight years after the financial crisis, a widespread public perception persists that not enough has been done to overhaul the institutions that are “too big to fail.” Calls to break up the biggest banks can be heard among politicians, analysts and even policymakers.

For their part, banking regulators have instead been quietly focusing on steadily pushing up an arcane but vital measure of the losses a bank could withstand in a crisis: its capital. Capital levels can be built up either by retaining profits or by raising money from investors.

The results of the annual stress tests are a marker of just how much progress the regulators have made in pushing banks to beef up the capital buffers that will protect the financial system in any future crisis.

And this year’s tests were “arguably the most stressful stress tests yet,” said Mark Zandi, Moody’s Analytics chief economist, noting that the big banks “must weather a downturn more severe than the Great Recession.”

The test results came as the banks themselves were preparing for a real-world stress test, Britain’s referendum on whether to leave the European Union. Given London’s importance to global finance and markets, the banks were preparing contingency plans if they needed to move their European bases.

Among the largest banks, Wells Fargo, Bank of America and JPMorgan Chase all suffered big losses in the Federal Reserve’s stress test. But all remained above their regulatory minimums.

And in one important measure — the Tier 1 leverage ratio — the 33 banks together would be 67 percent above the required minimum level even in the worst case of the stress test.

But even as the banks prove they have adequate capital, they are not out of the woods.

Next week, they will all have to pass another type of test from the Federal Reserve that is a more subjective measure of the banks’ planning and management processes. In the past, these so-called qualitative reviews have tripped up banks including Citigroup, which failed in 2014 even after demonstrating it had adequate capital.

On top of that, several Fed officials have recently said that for the nation’s biggest banks, future tests will become even more difficult, with stricter capital requirements.

Daniel K. Tarullo, the Fed governor who oversees regulation, told Bloomberg Television this month that regulators would probably seek additional capital surcharges for the country’s eight biggest banks.

“We need to have those eight most systemically important institutions more resilient than other banks in the economy,” he said.

The constant raising of capital requirements each year reduces the likelihood that the banks will ever need another round of taxpayer bailouts.

But the ever-evolving requirements have confounded bank executives and shareholders, who complain that the regulations are making it impossible for the banks to generate consistent profits.

Even as the economy has remained relatively stable over the last few years and the legal issues and losses from the crisis have been resolved, the share prices of large institutions like Bank of America have languished.

On Thursday, the banking industry’s trade group suggested that the stress tests had become unnecessarily burdensome.

“The tremendous effort banks have made to build capital and liquidity has allowed them to perform strongly even under scenarios that are unrealistically severe,” the American Bankers Association said in a statement. “This success has continued even as institutions are judged through an unnecessarily opaque standard.”

Some analysts have questioned whether regulators are purposely ramping up regulations to the point where it will no longer make sense to keep large commercial and investment banking operations as one entity — thus ending the threat of “too big to fail” institutions.

In the short term, Thursday’s stress test results, which are mandated by the Dodd-Frank financial overhaul law of 2010, could portend good news for the banks’ investors. The banks will probably be allowed to increase their dividends and buy back stock as part of their annual capital plans. The Fed will release its decision on whether to approve those capital plans on Wednesday.

In past years, a handful of banks have failed the tests and had to scale back their payouts to shareholders. The figures released Thursday indicated that the banks were likely to show improved results this year.

The Fed looked at how the banks would do this year in a recession that would lead to big losses in consumer banking, which has been an increasing concern in recent months.

The test also looked at how they would deal with negative interest rates, which have become more of a concern as central banks have struggled to raise the rates and depart from the policies they adopted immediately after the financial crisis. The test assumes that the banks could not make up for negative rates by charging their customers more to hold their deposits.

These assumptions posed less of a danger to banks with big trading and Wall Street operations, but led to bigger consumer losses.

While the tests posed extreme hypothetical events, real concerns about weakening consumer credit have plagued banks in recent months.

Investors have worried that weakening employment could bring about an end to a period of low defaults, particularly in automobile lending and credit cards — which have been two areas of growth for the banks.

© 2016 The New York Times Company