The stunning implosion of Archegos Capital Management, whose speculative bets roiled Wall Street, is now expected to cost Credit Suisse an even 5 billion francs ($5.5 billion), wiping out in one fell swoop five years of profits at its investment banking division.

Investors punished the stock, sending shares down 4.5% at the open Thursday in Zurich.

The scandal-plagued Swiss lender, which sold 203 million shares via mandatory convertibles on Thursday, said it had not yet fully unwound trades connected with Bill Hwang’s hedge fund and forecast further related headwinds of 600 million francs ($656 million) for the second quarter.

This comes on top of the 4.43 billion francs charge booked in the first three months of the year, pushing the group 757 million francs into the red, albeit less than initially feared.

Chief executive Thomas Gottstein called the losses generated by its New York prime brokerage operation "unacceptable" but blamed the opaque nature of Archegos for the problem.

“It's clear that a family office like that did not disclose positions like a normal hedge fund would do," Gottstein told reporters. "We will also learn from the regulators how other firms had managed."

Echoes of long-term capital

At the end of last month, JP Morgan raised its forecast for the banking sector’s collective Archego losses to $10 billion. Rivals Nomura and [hotlink]Morgan Stanley[/hotlink] have estimated their respective hit to be a fraction of Credit Suisse’s, however.

“It is an exceptional event. I think the last time the industry has seen anything like this was LTCM in terms of its size and consequence,” Credit Suisse chief financial officer David Mathers told analysts on Thursday, referring to the collapse in the 1990s of hedge fund Long-Term Capital Management.

Despite an otherwise strong underlying Q1 performance in investment banking led by a surge in underwriting, Credit Suisse initiated a strategic review with the aim of slimming the division’s leverage and assets.

The prime brokerage activities responsible for the Archegos disaster could shrink by a third over the course of this year to focus only on the bank’s most important clients who have large overlaps across the rest of its operations, it said.

Prime services were never a very attractive part of the business. "It is definitely not a business per se that we ever felt was extremely high returning," Gottstein said.

Credit Suisse shored up its balance sheet by issuing two notes convertible into roughly 8.3% of its outstanding shares. This will raise an estimated 1.7 billion francs in net proceeds and bolster its loss-absorbing capital well above regulatory minimum thresholds for solvency.

"We wanted to take the whole capital debate off the table," the Credit Suisse CEO told reporters, adding it would also protect the bank against volatile markets and inflationary fears.

The Archegos loss followed swiftly on the heels of the collapse of Greensill Capital, forcing Credit Suisse to liquidate investment funds, whose $10 billion in assets were linked to the now insolvent supply-chain finance firm.

Clients now face potentially billions in losses on what were supposedly safe, short-term investments. Nonetheless, management said there was no indication the bank might face a wave of redemptions. Net new assets in each of its three wealth management divisions were positive in March, according to finance chief Mathers, after it froze investors out from the Greensill funds.

Credit Suisse didn’t rule out additional charges to its income statement, either, already booking in a $30 million write-down in the quarter related to a bridge loan to Greensill.

Adding to investor jitters, the Swiss financial watchdog, FINMA, said on Thursday it has opened enforcement proceedings against the bank for its role in the Archegos and Greensill collapses.

Cleaning house

Earlier this month, investigations were launched into each affair, bonuses for the C-suite were eliminated, and the proposed dividend slashed by two-thirds. It also cost the job of both the division’s head, Brian Chin, and risk and compliance boss Lara Warner.

Their departures, however, cast a negative light on Gottstein. He promoted Chin to the role and expanded Warner’s remit this summer as part of an efficiency plan designed to save up to 450 million francs annually from next year. This looks to be a now fateful decision as Archegos-related losses will eat up a decade of those planned savings.

A defiant Gottstein vowed shortly afterward to stay on to right the ship together with the new chairman of the board come May, António Horta-Osório.

The current CEO of [hotlink]Lloyds Banking Group[/hotlink] has his work cut out for him: Amid the two single biggest global financial debacles so far this year, Credit Suisse found itself in the middle of both.

Credit Suisse's fortunes have soured quickly. Only six months ago, the outlook was brightening for the bank’s long-suffering shareholders. On the back of solid third-quarter results, it decided at the end of October to pay out the remaining half of the 2019 dividend cut at the request of Swiss regulators.

It simultaneously resumed share buybacks suspended because of the pandemic and earmarked a further billion francs for this year. The move marked the beginning of a 50% surge in the stock price, but the rally petered out earlier this year amid a steady stream of news, including the suspension of further stock repurchases.

As of late April, Credit Suisse has relinquished almost all its gains made in the past half-year.

Update, April 22, 2021: This article has been updated with comments from Credit Suisse throughout.

This story was originally featured on Fortune.com