Buy-back of securities: companies may repurchase shares via tender offer, open market or odd-lot subject to conditions. A company may buy back its own shares or other specified securities by tender offer to existing security-holders, from the open market via book-building or stock exchange, or from odd-lot holders; open market offers at or above a specified threshold are restricted. Buy-back through negotiated deals, spot transactions, private arrangements or on-exchange negotiated trades is prohibited. Insiders and others are forbidden to trade on unpublished buy-back information, and a company cannot make another buy-back offer within one year of closing a prior offer.