With help from a 39 percent rise in the value of Berkshire Hathaway shares over the past 12 months, Warren Buffett's donation to the Bill & Melinda Gates Foundation this year was the largest since his annual contributions began in 2006.
Buffett's gift of 17,458,431 shares is worth just over $2 billion at today's closing price of $115.01, a bit below the all-time high of $115.98 reached in mid-June.
Last July's contribution of 19.3 million shares was worth $1.5 billion at that day's closing price of $82.54.
In a 2006 letter to Microsoft's chairman and his wife, Buffett outlined a long-term schedule that has him donating 5 percent fewer shares each July year-over-year.
Over the eight years, Buffett has given the Gates Foundation more than 168 million shares, about a third of the 500 million shares he has pledged.
The total value of those gifts on the days they were made is almost $13 billion. At today's closing price, the shares would be worth $19.4 billion.
The billionaire also gave 1.75 million shares, worth about $201 million, to the Susan Thompson Buffett Foundation, in honor of his late first wife.
In total, the 22,870,529 shares contributed Monday are worth $2.6 billion.