-Large sales are usually done off exchanges because it's easier to agree on a price and leave the market unaffected by such a large transaction. -The governmen

-Large sales are usually done off exchanges because it's easier to agree on a price and leave the market unaffected by such a large transaction. -The government is probably not interested in taking a long time to sell these blocks. -Lastly, I imagine there are easily more than 10 individuals who are both financially willing and able to purchase blocks of this size.