Jim Whitehurst is stepping down as the president of International Business Machines (IBM  ) after only 14 months on the job.

Whitehurst joined IBM's c-suite just over a year ago, having been appointed as president after serving as CEO of Red Hat, which IBM acquired in 2019. Whitehurst was appointed a few months after Red Hat's acquisition, alongside the appointment of CEO Arvind Krishna.

At the time, many speculated that Whitehurst would succeed Krishna as CEO, with Krishna being seen as more of an interim CEO. The assumption was primarily based on Whitehurst's impressive stint at Red Hat, which became the first multi-billion dollar Linux company during Whitehurst's tenure.

Why Whitehurst is departing isn't currently known, as neither IBM nor Whitehurst himself have addressed the matter yet. Morgan Stanley analyst Katy Huberty noted, however, that "while investors are concerned that this has negative read-throughs for the health of IBM's hybrid cloud business and/or future outlook, we see this as a natural progression for Jim, as most of the Red Hat integration is complete."

Whitehurst's departure leaves a significant gap in IBM's c-suite, especially given his hard-to-replace expertise within cloud computing. With IBM's future staked largely in the cloud, and the market already having its share of titans such as Amazon Web Services (AMZN  ), the departure is certainly worth sweating over for investors.

Whitehurst's departure also casts doubt on relations between IBM and Red Hat, with the executive having been credited with maintaining employee morale as Red Hat underwent its acquisition. With Whitehurst now gone, Red Hat employees told ZDNet that anxiety was running high over fears that IBM would undo aspects of the subsidiary's corporate culture.

Wall Street certainly took notice of Whitehurst's departure, given the nosedive that IBM shares took on Friday. Shares plunged 4.7% on Friday, from $146.91 to $140. Tuesday saw no improvement for Big Blue, with shares trending down an additional 0.87% from Friday's close.