The Biggest Stock Buybacks of the Decade

Photo: Getty Images When cash-rich corporations authorize a share repurchase program, investors tend to see the move as a sign of confidence in the company's prospects. Common wisdom dictates that such transactions may carry an underlying message that a stock is "undervalued," leading management to put excess cash to work by investing in their own company's stock. However, buybacks can also be interpreted by investors as an attempt to stave off a drop in share price. Although stock prices will inevitably be impacted by changes in supply and demand and other market factors, how are common shares affected by a buyback? With data from Capital IQ, CNBC.com looked at some of the largest buyback programs in the past 10 years. Based on a sample of 20 of the biggest deals, valued at a minimum of $8 billion, the results show that stocks were up an average of seven percent six months after the initial announcement. So what are the biggest stock buybacks of the past decade? How did the stocks fare? Click ahead to find out!By Giovanny MoreanoPosted 30 March 2010

Photo: Getty Images Transaction value: $8 billion Shares repurchased: 171 million Announcement date: 3/15/07 Date completed: 1/31/08 Stock Performance After 3-Mos: 15% After 6-Mos: 22% During buyback period: 10% Transaction value: $8 billion Shares repurchased: 188 million Announcement date: 11/19/07 Date completed: 1/31/09 Stock Performance After 3-Mos: -28% After 6-Mos: -7% During buyback period: -2%

Photo: Getty Images Transaction value: $8.5 billion Shares repurchased: ~125 million Announcement date: 5/3/06 Date completed: 8/9/08 Stock Performance After 3-Mos: 9% After 6-Mos: 9% During buyback period: 20%

Photo: Getty Images Transaction value: ~$8.5 billion Shares repurchased: 214 million Announcement date: 3/3/05 Date completed: 9/11/06 Stock Performance After 3-Mos: 1% After 6-Mos: -13% During buyback period: -47%

Photo: Getty Images Transaction value: $8.89 billion Shares repurchased: ~249 million Announcement date: 10/29/01 Date completed: 9/12/07 Stock Performance After 3-Mos: -8% After 6-Mos: -1% During buyback period: 6%

Photo: Getty Images Transaction value:  ~$9.31 billionShares repurchased:  200 millionAnnouncement date:  3/22/05Date completed: 6/30/06Stock Performance After 3-Mos: 6%After 6-Mos: -5%During buyback period: 9%

Photo: Getty Images Transaction value: $10 billionShares repurchased: ~216 millionAnnouncement date:  2/1/01Date completed: 3/31/03Stock Performance After 3-Mos: 14%After 6-Mos: 3%During buyback period: -32%

Photo: Getty Images Transaction value:  $10.39 billionShares repurchased:  200 millionAnnouncement date:  4/26/06Date completed: 9/30/07Stock Performance After 3-Mos: 8%After 6-Mos: 15%During buyback period: 8%

Photo: Getty Images Total transaction value: $11.6 billion Shares repurchased: 223 million* Announcement date: 5/31/07 Date completed: 6/4/09 Stock Performance After 3-Mos: -8% After 6-Mos: 2% During buyback period: 8% *As of 4/30/09, Wal-Mart had repurchased 223 million shares for a total cost of $10.9 billion. On 3/5/09 the Board resumed the share repurchase program

Photo: Getty Images Transaction value: ~ $12.07 billion Shares repurchased: 220 million Announcement date: 11/18/02 Date completed: 3/31/08 Stock Performance After 3-Mos: 20% After 6-Mos: 9% During buyback period: 33%

Photo: Getty Images Transaction value: $13.5 billion Shares repurchased: 351 million Announcement date: 3/5/06 Date completed: 12/11/07 Stock Performance After 3-Mos: -5% After 6-Mos: 13% During buyback period: 41%

Photo: Getty Images Transaction value: ~$15 billion Shares repurchased: 326 million Announcement date: 4/14/05 Date completed: 8/31/06 Stock Performance After 3-Mos: -0.2% After 6-Mos: -2% During buyback period:8%

Photo: Getty Images Transaction value: $15 billion Shares repurchased: 133 millionAnnouncement date: 2/26/08 Date completed: 11/30/09 Stock Performance After 3-Mos: 13% After 6-Mos: 12% During buyback period: 15% Transaction value: $15 billion Shares repurchased: 138 million Announcement date: 4/24/07 Date completed: 3/31/08 Stock Performance After 3-Mos: 18% After 6-Mos: 15% During buyback period: 17%

Photo: Getty Images Transaction value: $15.14 billion Shares repurchased: 192 million Announcement date: 1/12/07 Date completed: 12/31/08 Stock Performance After 3-Mos: 12% After 6-Mos: 38% During buyback period: -16%

Photo: Getty Images Transaction value: $20 billion Shares repurchased: 1.11 billion Announcement date: 8/3/05 Date completed: 8/31/07 Stock Performance After 3-Mos: 3% After 6-Mos: 4% During buyback period: 9%

Photo: Getty Images Value of the transaction: $20.1 billion Shares repurchased: 358 million Announcement date: 1/28/05 Date completed: 7/21/06 Stock Performance After 3-Mos: -3% After 6-Mos: 0.1% During buyback period: 1%

Photo: Getty Images Transaction value: $27 billionShares repurchased:  ~738 millionAnnouncement date:  12/10/04Date completed: 12/31/07Stock Performance After 3-Mos: 1%After 6-Mos: 2%During buyback period: 3%

Photo: Getty Images Transaction value: $36.2 billion Shares repurchased: 1.22 billion Announcement date: 7/20/06 Date completed: 8/31/08 Stock Performance After 3-Mos: 22% After 6-Mos: 33%During buyback period: 17% Transaction Value: $30 billion Shares repurchased: 1.16 billion Announcement date: 7/20/04 Date completed: 6/20/06 Stock Performance After 3-Mos: 1% After 6-Mos: -7% During buyback period: -19.3%

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