Ann: June 2023 Quarterly Activities and Cash Flow Report, page-43

From what I understand it is an algorithm that works out how many to buy (and sell) to accumulate the desired amount at the lowest price based around the listed number of buyers and sellers on market at any point in time. Buy large lumps and the price rises steadily, buy in dribs and drabs (ridiculously small) and the SP is unaffected. It also tends to draw in more sellers at lower prices. Something like that anyway. Clever stuff.