Anthony Behar/Sipa/AP

Microsoft's stock surged to a historic peak after announcing Sam Altman, former chief of OpenAI, would lead its AI innovation division. This propelled shares of the tech giant to a 2.1% increase, reaching an all-time high of $377.44 on Monday, surpassing its previous peak of $376.17.

This rise followed a 1.7% dip in Microsoft's shares on Friday, coinciding with Altman's removal from OpenAI in a boardroom upheaval. As Microsoft holds a significant $13 billion stake in the AI firm, speculation swirled about Altman's potential return, which concluded with his hiring. Greg Brockman, OpenAI's co-founder who departed post-Altman's dismissal, also joined Microsoft.

Emmett Shear, former CEO of Twitch under Amazon, steps in as OpenAI's interim CEO, succeeding Mira Murati.

Microsoft's stock has surged by 56% this year and is among the select "Magnificent Seven" driving substantial market returns, fueled by investor confidence in AI's tech dominance.

Wedbush Securities' tech analyst Dan Ives reaffirmed a $425 price target for Microsoft's stock post-Altman and Brockman's appointments. Ives highlighted Microsoft's fortified AI standing with Altman and Brockman in his Monday note.

The market responded positively to this news, evident in other "Magnificent Seven" members' performance. Nvidia's shares climbed by 2.3% to $504.20, setting a record-high close before its impending earnings report on Tuesday.