A tender offer is a kind of takeover bid for a public company.
In a tender offer, a bidder attempts to take over a public company by offering to purchase outstanding shares directly from the current shareholders at a stated price. The goal is to accumulate enough shares to gain a controlling stake in the business.
In order to convince shareholders to part with their shares, they are usually offered a premium over the current market price of those shares. However, the offer is usually conditional on enough shareholders agreeing to sell to provide the controlling stake in the business.