Companies can repurchase shares using various methods:
A tender offer involves the company proposing to acquire shares from existing security holders at a specified price.
Open market repurchases are executed via the stock exchange, often following a book-building process.
Repurchase programs may also specifically target odd-lot holders (small shareholders).
However, purchasing shares through negotiated deals on the stock exchange is neither a standard nor an allowed method for buybacks, as it is considered insider trading.