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# 437 Milane Duncan Frantz $5.19B

Random fact: Brother Scott inherited his choice of his father's hunting guns.


Frantz and her three siblings control one-third of Enterprise Products Partners, a publicly traded midstream energy company. The Houston-based business has $62 billion in assets including about 50,000 miles of pipelines. Her father, Dan Duncan, co-founded Enterprise Products Partners in 1968 and died in 2010.

As of :
Last change -$29.4M ( -0.6%)
YTD change -$1.49B ( -22.3%)
Industry Energy
Biggest asset Cash
Citizenship United States
Age 50
Wealth Inherited
View net worth over:   Max 1 year 1 quarter 1 month 1 week

Relative Value

Milane Duncan Frantz's net worth of $5.19B can buy ...

troy ounces of gold
barrels of crude oil

... and is equivalent to ...

of the GDP of the United States
of the total wealth of the 500 richest people in the world
of the top 100 U.S. college endowments
of the top 200 U.S. executives’ total awarded compensation
of U.S. existing home sales
times the median U.S. household income

Latest News

Net Worth Summary

Private asset
Public asset
Misc. liabilities
Confidence rating:

Milane Duncan Frantz's fortune stems from her share of stock inherited in Enterprise Products Partners, a Houston-based midstream energy business with $62 billion in assets and about 50,000 miles of pipelines, according to the 2019 annual report.

Frantz is one of four children of Enterprise Products Partners founder Dan Duncan and his wife, Jan. Following his death in 2010, Frantz and her two sisters, Randa Duncan Williams and Dannine Duncan Avara, and a brother, Scott Daniel Duncan, inherited the family trusts that make the siblings the largest shareholding group of the company. This analysis asserts the siblings split their father's share equally, based on his will filed in Harris County, Texas, probate court on April 14, 2010. In that document, Duncan acknowledges the four as his descendants and wills them the entities which held the vast majority of his shares without indicating any uneven split among them.

The family's interest in Enterprise Products has collected more than $9 billion in cash distributions since October 1998, according to data compiled by Bloomberg. These dividends have been adjusted for stock purchases taxes and appreciated with an allocation of 30% each in cash, U.S. bonds and large cap stocks, and 10% commodities. Dan Duncan died in 2010, when there was no estate tax in the U.S.

Of the 702 million units under family control, 108 million units are pledged as collateral by Duncan family investment vehicles and aren't included in the net worth calculation, according to the 2019 annual report filed with the Securities and Exchange Commission. Frantz is credited with a quarter of the Duncan family's holdings, or about 8% of the company.

Enterprise Products spokesman Rick Rainey declined to comment on the family members' net worth calculations.


Birthdate: 1/1/1970
Family: Married, No children

Milane Duncan Frantz is one of the four children of Dan Duncan, founder of Enterprise Products Partners. With her three siblings, she splits ownership of Enterprise Products Partners, the closely held entity that controls one-third of the publicly traded company. Her father founded Enterprise Products in 1968 -- with $10,000 and two fuel trucks -- as a natural gas liquids wholesaler.

He later expanded into crude pipelines, fuel storage and natural gas processing. By the time of his death in March 2010, he had parlayed that initial investment into a company with a market capitalization of about $31 billion. In the last decade of his leadership, the company delivered an annual 20 percent return on investment. Duncan had four children with his wife, Jan, who's still alive. Randa is the oldest child, followed by another sister, Dannine Duncan Avara, and a brother, Scott Daniel Duncan.

Frantz is a board member of the Baylor College of Medicine in Houston. She and her husband, Matthew J. Frantz, were married in Harris County, Texas in 2001. They live in Houston, according to public records.

  • 1968 Dan Duncan forms Enterprise as natural gas liquids distributor.
  • 1969 Milane Duncan is born to Jan and Dan Duncan.
  • 1972 Enterprise constructs pipelines in Mont Belvieu, Texas.
  • 1980 Firm begins building 35,000 barrels-a-day Mont Belvieu, Texas fractionator.
  • 1998 Company sells shares in an initial public offering at $22 a unit.
  • 2001 Marries Matthew J. Frantz.
  • 2010 Father Dan Duncan, Enterprise Products founder, dies.
  • 2015 Enterprise completes sale of offshore pipelines for $1.5 billion.