John Patrick Grayken (born June 1956) is an American-born Irish billionaire financier, the founder and chairman of the private equity firm Lone Star Funds.
[1][4] Grayken first worked at Morgan Stanley, before joining the RMB Realty Group, the real estate investment firm of Texas billionaire Robert Bass.
[8] The fund aimed to buy mortgage-related assets from the banking industry, including from the Resolution Trust Corporation.
[16] Grayken and his wife made a 2022 donation of £50 million to the Great Ormond Street Hospital, earmarking the funds for researching treatment of childhood illnesses.
It is alleged that he personally became the beneficial owner of RattanIndia Finance, when he had told other shareholders that Lone Star Funds would do so.