Ann: TAW and AMAL complete First Shipment of Lithium Concentrate, page-136

It's usually just about keeping an orderly market. Buying 1.2m shares on market would push the price up significantly, on the flip side selling 1.2m shares would push it down significantly. Therefore if you have a party that wants to sell and one who wants to buy it's easier just to cross off market as a win/win for both parties.