At that moment, Mr. Dimon lay in a bed at a hospital named for financier Sandy Weill. Mr. Weill, his onetime mentor, had abruptly fired him from Citigroup two decades earlier in a power struggle.

He ached all over. His heart, getting used to its new parts, thumped so strongly his daughters felt it when they hugged him. His scar looked like a zipper that would open a jacket right down the middle of his chest. There were tubes and probes in his lungs, arteries and jugular vein.

After a few days, the medical staff started pulling the tubes and electrodes out of his body. On March 12, a week after surgery, Mr. Dimon was released from the hospital.

Friday, March 13, was Mr. Dimon's 64th birthday. He joined a call with his top executives, and they sang "Happy Birthday" to him.

That weekend, the coronavirus shut down America.

Schools and nonessential businesses closed. People were told to stay home and avoid socializing outside their households. On Sunday, March 15, the Fed slashed interest rates to near zero, its second emergency cut in as many weeks.

On a conference call with the leaders of America's biggest banks that evening, Morgan Stanley Chief Executive James Gorman suggested they all suspend share repurchases to free up funds to lend to consumers and businesses. Mr. Smith agreed.

By Monday morning, the financial world looked to many to be headed for a crisis. Stocks again tripped their circuit breakers. Investors dumped shares and other securities -- anything that looked even remotely risky -- and stockpiled cash.

Mr. Dimon dialed into the bank's executive meeting. His voice was still hoarse, but he wasn't acting too sick.

Among the options on the table: borrowing from the Fed's emergency-lending program. The discount window, as it is known, is meant to help banks weather short-term funding crunches, typically with an overnight loan. There was a big stigma attached to borrowing directly from the Fed -- banks more or less abandoned it after the financial crisis. Do it, Mr. Dimon said.

Later that day, eight of the biggest U.S. banks announced they would all borrow from the window. None of them needed the Fed to backstop them that night, but the future was deeply uncertain. If they acted as a group now, they would signal that borrowing in the future wasn't cause for alarm.

On March 23, the Federal Reserve rolled out an aggressive plan to flood the markets with money. It would lend to businesses and investors and purchase unlimited amounts of government debt -- whatever was necessary to boost the ailing economy.

Four days later, Mr. Trump signed a $2 trillion stimulus bill that included direct payments to most Americans, an extra $600 a week in unemployment benefits, loans and grants for struggling industries and a small-business bailout. Much of the money would flow through America's banks, including JPMorgan.

The fiscal and monetary stimulus revived battered markets. Companies that had hoarded cash by maxing out their credit lines raced to sell new debt to eager investors.

Still, by the end of March, confirmed U.S. cases of Covid-19 had crossed 180,000, and the U.S. Navy hospital ship Comfort was heading into New York harbor.

Some 10 million people had lost their jobs. Bank stocks were plummeting, as investors worried they would face surges in losses. Consumer spending had cratered, and a recession that suddenly looked like the worst since the Great Depression was looming.

Mr. Dimon, secluded at his Manhattan apartment, was under the care of his wife. He joined virtual operating committee gatherings, but left decisions to them. In recent years, Mr. Dimon had delegated more authority, but he remained deeply embedded in every business line and thrives in a crisis.

Doctors cleared him to return to work full-time remotely the first week of April. He was warned to heed dizziness and pain. By then, he had decamped to his house in Bedford, a Westchester suburb. Still building strength, he took walks of several miles around the neighborhood. More extended family arrived to be with him.

Mr. Dimon got to work preparing JPMorgan for a painful recession. Each morning, he was given reports on the bank's exposure to companies in the news. Executives spent hours debating an ever-shifting set of five economic scenarios, from best-case to worst-case. To figure out how much the bank needed to set aside if people and businesses stopped paying them back for loans, they had to assign probabilities to all five. But they couldn't agree on where the economy was headed.

The bank's researchers and economists needed data that was being revised in real time. They tracked future Broadway ticket sales and Google search trends for "unemployment benefits." Some studied what happened when hurricanes wiped out cities.

Mr. Dimon wanted to prepare for the worst-case scenario. But the most-likely picture, executives decided, was a grim second quarter during which unemployment would rise above 10% and gross domestic product would plunge at a breathtaking annualized rate of 25%.

To estimate how many loans would default, they paired the broad economic forecasts with reams of data on customers. The roughly 150 variables included where they lived and worked and what kind of house they owned.

They were surprised at how customers were behaving.

Unemployment had soared, but customers were paying down credit-card debt instead of racking up balances. Customers flooded the bank with relief requests but kept paying on their loans. Spending on Chase credit cards plunged. Savings swelled. The usual correlation between rising unemployment and deteriorating consumer finances had broken down.

Mr. Dimon was convinced that the flood of government money was easing the symptoms of the recession while masking the economy's underlying illness.

"Every piece of data seems distorted," Mr. Dimon told executives. "A recession is happening. We just can't see all of it."

On April 14, the bank set aside $8.3 billion to cover potential losses on loans, far more than analysts had predicted. The bank's quarterly profit fell by nearly 70%.

Already, the bank's dire forecasts for the economy had worsened. It now expected 20% unemployment and a 40% annualized drop in GDP in the second quarter.

The spring and early summer brought better news. Infections fell sharply in New York and the hard-hit northeast. The unemployment rate peaked at 14.7% in April, below the bank's expectations. Cities and states marched toward reopening.

Mr. Dimon again went against the optimistic thinking and believed that many of the layoffs workers assumed were temporary would eventually become permanent. When that happened, spending would drop again, forcing businesses to cut more jobs.

On June 9, Mr. Dimon returned to JPMorgan's nearly empty Madison Avenue headquarters and started working there most days. His doctors had him monitor his blood pressure at his desk as a precaution, and he was watching his heart rate on his smartwatch.

In late June, he went to Washington to meet with Mr. Mnuchin and lawmakers to urge more action.

For years, Mr. Dimon has used JPMorgan as a platform to weigh in on the nation's problems and offer solutions, from taxes to infrastructure to education. He has been building an internal think tank and a policy group that study the unrivaled data that comes from handling the daily checking accounts of millions of Americans and small businesses.

Mr. Dimon believed the data could help officials understand the severity of what the economy was facing. The shutdowns had hurt many, but the pain wasn't equally spread. Heading into the crisis, half of all small businesses held less than 15 days of cash on hand. They were now hoarding cash, but partly because they had stopped paying suppliers and workers. Minority businesses, in particular, were in trouble.

Meanwhile, JPMorgan customers continued to behave in unexpected ways. They were still holding on to 30% of their stimulus checks, a savings rate that stunned executives.

In July, the bank put aside another $10.5 billion for potential losses on loans, much of it to cover corporate loans that could go bad. Still, JPMorgan posted more revenue than it ever had in a quarter.

By the middle of August, the S&P 500 was setting new records, but bank stocks were down, as investors worried about their profitability. The only thing that seemed to lift them was talk of stimulus.

In September, Mr. Dimon made another trip to Washington, determined to share evidence that the first round of stimulus was wearing off. Customers on unemployment had used their topped-up benefits to pad their savings. In August, after those extra payments ended, they had burned through two-thirds of it.

Still, Mr. Dimon was quietly talking about a deal that indicated his confidence in the bank's own health. Eaton Vance Corp., an asset manager with $500 billion in assets, was for sale. It was exactly the kind of acquisition Mr. Dimon had telegraphed at the February investor day: a chance to bring in high-margin assets that aren't easily grown in-house. In the end, he walked away. Morgan Stanley won the prize with a $7 billion bid.

In October, JPMorgan surprised the market with its third-quarter results: Profit had rebounded to pre-pandemic levels. Markets had staged a remarkable comeback from March and companies rushed to raise debt and equity, boosting the bank's Wall Street businesses.

The bank released some of the money it had been storing for losses on loans. Mr. Dimon tried again to tamp down any enthusiasm and warned that the recovery could stall without more stimulus, leading to a double-dip recession. If that happened, the bank could be as much as $20 billion short of what it would need to cover soured loans, he said.

The presidential election added more volatility. Stocks moved up and down as investors bet on the outcome and the likelihood for more stimulus.

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12-24-20 1012ET