As of October 2021, here are the ten largest stock buybacks announced in 2021:
1. Alphabet Inc. (Google): $50 billion buyback.
2. Microsoft Corporation: $60 billion buyback.
3. Salesforce.com, Inc.: $10 billion buyback.
4. Alibaba Group Holding Limited: $15 billion buyback.
5. McDonald’s Corporation: $25 billion buyback.
6. Procter & Gamble Company: $18 billion buyback.
7. JPMorgan Chase & Co.: $30 billion buyback.
8. Home Depot, Inc.: $60 billion buyback.
9. Mastercard Incorporated: $8 billion buyback.
10. General Electric Company: $10 billion buyback.
Please note that these figures are subject to change as new announcements are made, and it is always recommended to verify the most recent information from official sources or financial news platforms.