20110907 carol bartz yahoo
Yahoo! CEO Carol Bartz at the Yahoo! headquarters April 27, 2009 in Sunnyvale, Calif. - 

Jeremy Hobson: News of two big shakeups in corporate America. The board of Yahoo, which has struggled to compete with Google and Facebook, has ousted CEO Carol Bartz. And two senior executives are out at Bank of America.

Marketplace's Amy Scott tells us why these companies decided it was time for a change.

Amy Scott: Both of these moves are related at least partly to the whims of the stock market. In Yahoo's case, Carol Bartz was brought in not quite three years ago to turn the company around and raise its share price.

Howard Wheeldon is a strategist at BGC Partners in London. He says since then, not much has changed. While rivals have grown, Yahoo's stock is basically flat.

Howard Wheeldon: It is pretty well the same company now that it was three years ago. That is, in the eyes of big shareholders, probably unacceptable.

The Bank of America shakeup comes as its stock has lost half its value this year. The banks's heads of consumer banking and global wealth and investment management resigned as part of a reorganization led by CEO Brian Moynihan.

At least for now, shareholders in both companies seemed to like the news. Bank of America's stock rose -- barely. In after-hours trading, Yahoo climbed six percent. Whether these strategies work long-term is another question.

I'm Amy Scott for Marketplace.

Follow Amy Scott at @amyreports