Eduardo Munoz / REUTERS

Commuters are reflected in stone as they walk past the JP Morgan headquarters in New York.

When JPMorgan reports its quarterly results Friday morning, most investors will be eager to hear just one key piece of information: How much of a splash did the London Whale make for the bank?

In mid-May, the bank announced it had sustained a multibillion-dollar loss that originated in its London office because of a failed hedging strategy undertaken by Bruno Iksil, nicknamed “The London Whale” because of the size of the trading positions he took.

Since then, JPMorgan CEO Jamie Dimon has appeared on Capitol Hill to explain the massive loss, which the New York Times reports has grown from the $2 billion originally reported to about $5 billion.

“Investors want to understand what happened, who knew what and when,” Betsy Graseck, a managing director for Morgan Stanley, told CNBC Thursday.

Bank earnings don’t usually attract much attention outside the Wall Street community of analysts, traders and other financial industry observers. The JPMorgan report is likely to spur greater interest because of the massive trading loss, which has enraged public opinion and led to Dimon appearing on television and two Congressional panels to own up to his company’s mistakes.

Graseck said it will be important for Dimon, for investors and for the public to set the record straight on the trading loss. He needs to detail exactly how much of the disastrous trade has been “unwound” so the company can move ahead and avoid any future volatility in its stock price that may arise from uncertainly over deeper losses.

“The question is how much [of the trade] is left to go, and what is the volatility on what’s left,” Graseck said.

Investors and the public will want to hear details of how much money will be recovered from top executives at the bank involved in the botched trade.

When he appeared before lawmakers last month to explain his bank’s multi-billion dollar losses, Dimon said the trading debacle will lead to “clawbacks” -- efforts to recover compensation paid to employees whose performance was later found to have harmed the company and shareholders.

Ina Drew, the former chief investment officer who oversaw the London office where the bank’s botched trade originated, is likely to see her pay curtailed, according to reports, and so is Iksil, according to a report in the U.K’s Telegraph newspaper.

Since May a handful of other financial scandals have hit the headlines, including news of a global rate-fixing scandal at U.K. bank Barclays and some $200 million missing from customer accounts at Iowa brokerage PFGBest.

These negative headlines are threatening to erode investor confidence in the financial services industry, said Bart Naylor, an expert in financial regulation at the consumer advocacy group Public Citizen. Dimon is likely to want to restore investor confidence after the trading error, which has wiped $23 billion off JPMorgan’s market value since it was announced on May 10 and has marred his reputation as one of the industry’s best risk managers.

Given his initial, sanguine response to the trading loss, when he called it a “tempest in a teacup,” Dimon appears to have been unable initially to comprehend the gravity of the error, Naylor said. Now, with the bank’s share price down 16 percent since it reported the loss, shareholders are showing they have “far less confidence” in the bank’s ability to judge risk, he added.

“He’s depending on people who have skills he doesn’t understand,” Naylor said. “That may be okay for a CEO in the computer software industry who doesn’t need know how to write code, but [at a bank] this has had a material effect on the company, and shareholders are affected.”

JPMorgan is the first big bank to report its earnings for the second quarter, and it will be watched as a barometer for the rest of the industry. Analysts expect the bank to report net income that is about half the $5.4 billion reported for the same period last year, which would mean that the trading loss wipes out much of the profit for the quarter. JPMorgan also reported a net income of $5.4 billion in the first quarter of 2012.

Whatever the quarterly results, Dimon still has a fan in billionaire investor Warren Buffett, who in an interview on CNBC Thursday endorsed the bank CEO as “one of the best bankers in the world” who “understands banking and understands risk.”

“If I owned a bank in Omaha and I could get Jamie to run it for me I’d be very happy,” he said. “Jamie understands risks,” he added, noting that the actions of the London trader Iksil were by one person who “went off the reservation” and didn’t represent company policy.