-- Updated with stock move and potential Yahoo! breakup strategy.
Tumultuous markets, slumping sales and stalled turnaround strategies put a lot of pressure on CEOs. And as Bartz ouster showed, it's only a matter of time until the board decides to shake things up.
Bartz's nearly three year run as Yahoo! chief came to an end Tuesday when she received a call from Yahoo! chairman Roy Bostock, who apparently told her it was time for a change. CFO Tim Morse takes over on an interim basis until the board finds a permanent replacement.Wall Street cheered the move. Yahoo! shares, which rose as much as 7% cooled slightly but were still trading up 4% Wednesday on the news and the potential breakup strategy for the stumbling `Net giant. How jazzed were investors by Bartz removal? Yahoo's market cap jumped by more than $1 billion immediately following the news. After a hopeful start, Bartz had lost some of her gruff charm. Bartz may eventually be remembered for the fact that she ran Yahoo! while the company sat on the sidelines during the social media and mobile Internet boom. But Bartz isn't alone. There are other tech titans that have struggled to meet market challenges and, in some cases, have driven businesses off course. Here are four other tech CEOs in the hot seat who may get a similar call from their boards. The ranking is in order of stock declines for the year.