General Motors Acceptance Corporation (GMAC) was the financial services arm of General Motors (GM), originally established in 1919 to support the automaker's sales. Its core mission was to provide financing to both consumers purchasing GM vehicles and the dealerships stocking them. For decades, GMAC was a titan of American finance, pioneering the concept of mass-market auto loans and becoming a key engine of GM's growth. By making cars more affordable through credit, it fueled the rise of the American automobile culture. However, its story took a dramatic turn when it expanded aggressively into the U.S. mortgage market. This diversification, particularly into risky subprime mortgage lending, led to catastrophic losses during the 2008 Financial Crisis. Facing collapse, GMAC received a multi-billion dollar government bailout and was restructured. It eventually shed its old identity and re-emerged as Ally Financial Inc., a publicly traded, independent bank holding company.
At its heart, GMAC was a classic captive finance company, a subsidiary whose purpose is to finance the sales of its parent company's products. This created a powerful, self-reinforcing cycle for General Motors.
This symbiotic relationship was highly effective. More financing from GMAC led to more sales for GM, which in turn created more financing opportunities for GMAC. For a long time, it was a smooth-running profit machine. The risk, however, was its complete dependence on the health of its parent company and the auto market.
GMAC's ambition eventually extended beyond the auto lot. In the 1980s and 1990s, it diversified into a wide range of financial services, including insurance and, most fatefully, home mortgages through its subsidiary, Residential Capital (ResCap).
While auto lending was its expertise, the mortgage business was a different beast. ResCap became one of the largest originators of subprime mortgages in the United States. When the housing bubble burst, these loans soured at an alarming rate. The massive losses at ResCap created a black hole on GMAC's balance sheet, threatening to pull the entire company—and its parent, GM—down with it. The crisis was so severe that GMAC and GM were deemed a systemic risk to the U.S. economy, leading to a government bailout under the Troubled Asset Relief Program (TARP).
As a condition of the bailout, GMAC was required to convert into a bank holding company. This move gave it access to more stable funding from the Federal Reserve but also subjected it to stricter regulatory oversight. In 2010, the company rebranded itself as Ally Financial, a symbolic break from its troubled past and its captive relationship with GM. Ally has since rebuilt itself into a successful and diversified online bank, though automotive finance remains a core part of its business.
The story of GMAC is a goldmine of lessons for the value investor.