Despite a quarter that was marked by unrest in the streets of Hong Kong, HSBC reported relatively robust results on Monday (local time) that beat the Street's expectations. And in addition to announcing a share buyback of $1 billion (which is half the size of last year's), the bank followed several of its peers in announcing mass layoffs (HSBC will cut roughly 2% - approximately 4,000 jobs - from its global workforce) while also revealing that its CEO John Flint, who has been in the job only 18 months, will leave the bank as its board looks for "a different approach" on growth, resource allocation and execution.

Like many of its fellow global banks, HSBC shares have underperformed during Flint's tenure, which could be one reason for his sudden departure. Noel Quinn, who has led global commercial banking at HSBC since December 2015, will take over for Flint on an interim basis, SCMP reports. The news sent HSBC shares down roughly 2% to their lowest intraday level in 9 months.

"In the increasingly complex and challenging global environment in which the bank operates, the board agrees that a change is needed - and John agrees - to make the most of the significant opportunities ahead of us," HSBC's Chairman Mark Tucker said on a conference call. "This is a decision about the future."

Flint, 51, joined the bank in 1989 spent his entire career there. He led the lender's retail banking and wealth management businesses before taking over for retiring CEO Stuart Gulliver in February 2018.

The bank's board insisted that there hadn't been a clash of personalities and no disagreement over strategy, but that the bank's directors had decided it was time for Flint to go.

"There has been no personality clash. There has been no disagreement over strategy," Tucker said. "This is a unanimous decision of the HSBC non-executives [on the board]. Personalities have not been a factor in this at all."