A third party that rescues a target company from a hostile takeover is called a white knight.
The white knight is a friendly acquirer chosen or welcomed by the target’s board and management. It may offer a higher price, friendlier terms, or a structure that preserves more of the target’s existing leadership and operations. By completing an agreed transaction, it can block or outbid the unwanted “black knight.”
The term is narrower than simply “rescuer.” A white knight usually acquires control or the company itself. A white squire, by contrast, buys a significant minority stake and helps fend off the hostile bidder without taking over the target. A gray knight is a third bidder whose intentions appear less friendly than the white knight’s but potentially more acceptable than the original hostile bidder’s.
Examples of white-knight behavior include JPMorgan Chase’s 2008 acquisition of Bear Stearns during the financial crisis and Fiat’s 2009 move to save Chrysler from collapse. In both cases, the label reflects the target’s preferred alternative, not a guarantee that every later outcome will be favorable.