Global Investment Holdings | 8,117 followers on LinkedIn. Global Investment Holdings became the leading independent brokerage and investment banking firm in Turkey soon after its establishment in 1990. The Company has played a vital role in the development of Turkish capital markets by paving the way for many of the country’s leading businesses to meet international businesses for the first time. The Company transformed into an investment portfolio company in late 2004 drawing on its appetite for growing investments and its extensive investment banking experience.