Dimensional Fund Advisors

Dimensional Fund Advisors, L.P. (branded Dimensional abbreviated DFA ) is a privately-owned investment firm headquartered in Austin, Texas. Dimensional was founded in Brooklyn in 1981 by David Booth, Rex Sinquefield and Larry Klotz. The company has affiliates within 15 offices in the U.S., Canada, U.K., Germany, Netherlands, Australia, Singapore, and Japan. Dimensional maintains additional U.S. offices in Charlotte, North Carolina and Santa Monica, California.

The company’s founders studied at the University of Chicago under Eugene Fama. Kenneth French is co-chair of the firm's investment research committee. DFA's investment strategy is based on application of the efficient market hypothesis. Dimensional was one of the earliest firms to offer passive investing and "runs the oldest small-cap index fund" in the United States. However, the firm's versions of index funds have the flexibility to trade daily and skew towards smaller company stocks and value stocks; They operate differently from most index funds which rebalance on specific dates and are weighted by market capitalization. This strategy results in regulators, such as the SEC, and some analysts  describing the funds as actively managed. The company offers equity and fixed income mutual funds, Exchange-traded funds, separately managed accounts, and model portfolios.

In 2009, Dimensional acquired SmartNest, a retirement planning computer software company. Researcher Robert C. Merton left SmartNest's board after the purchase and became a Resident Scientist at Dimensional.

In November 2020, the firm announced it was augmenting its strictly advisor-access and institutional only mutual fund business model by offering openly-accessed exchange-traded funds.