After Credit Suisse said it had lost nearly $5 billion over soured trades that a small unit of its investment bank made with Archegos Capital Management, worried employees peppered Thomas Gottstein, the chief executive, with questions.

One wanted to know if bankers who weren’t involved would have to sacrifice pay over the losses. Another asked why the entire investment bank was tarnished by the actions of one errant unit.

Those questions, described by two people who attended an April 6 call with managers where those questions were asked, reflected a deeper set of concerns that have dogged Credit Suisse, its employees and shareholders for years: Can its investment bank be fixed?

Credit Suisse’s longstanding love-hate relationship with its own investment bank is on bad terms once again. After a series of missteps in the past year — including the fallout from Archegos, the investment firm run by Bill Hwang that went belly up — regulators are investigating, shareholders are angry and employee morale is flagging.

That is prompting questions about whether Credit Suisse — whose ambitions transformed it from its Swiss roots to a global bank serving some of the world’s richest people, as well as large companies and hedge funds — should scale back and focus on what it knows best: managing money for the wealthy.

But risk problems lingered under the surface: The departure of longtime bankers during his tenure had cost Credit Suisse valuable institutional knowledge, and the bank had built an increased zeal for working with up-and-comers, like Luckin Coffee and Greensill.

Snowballing scandals

In finance, risk management — the ability to take into account a sometimes-volatile mix of bank positions, market activities, assets and liabilities, and reputational and technological concerns to foresee potential losses — is a crucial skill.

But the bank’s approach has been extremely technical, said Arturo Bris, a professor of finance at the IMD business school in Lausanne, Switzerland. An overreliance on calculation can be a problem if those in charge aren’t taking a holistic view.

“Most of these failures have much more to do with human mistakes,” he said. “I don’t think they’re good risk managers.”

Consider the Archegos collapse: The prime brokerage head of risk who oversaw Credit Suisse’s dealings with Archegos had once handled the bank’s sales relationship with the firm. Above him was a chief risk officer whose background was in finance and compliance — not risk.

Credit Suisse has held more than a half-dozen executives responsible for its recent stumbles. The last day for Brian Chin, the chief executive of the investment bank, was Friday. Lara Warner, the chief risk and compliance officer, already departed. And then there was the departure of Mr. Gottschling, the board’s risk committee leader, who did not seek re-election at the annual meeting.

Now Mr. Horta-Osório will have to figure out whether Credit Suisse can steady its investment bank with personnel changes, or if a more serious makeover is in order.

If he chooses to make big changes, he may have to move swiftly.

“Shareholders and employees cannot wait for months for a new strategy,” said Manuel Ammann, a professor at the Swiss Institute for Banking and Finance at the University of St. Gallen. “They need to deliver fast.”