Bloomberg Billionaires Index

View profiles for each of the world’s 500 richest people, see the biggest movers, and compare fortunes or track returns.

# 358 Leonard Stern $6.77B

Random fact: Son was a reporter at Spy magazine before joining family business.


Stern is chairman of Hartz Mountain Industries, a closely held New Jersey real estate developer. Hartz Mountain has more than 45 million square feet of US office, industrial and retail space in more than 260 buildings, as well as residential apartments and hotels. Stern sold his pet supplies business in 2000.

As of :
Last change -$25.0M ( -0.4%)
YTD change +$268M ( +4.1%)
Biggest asset Hartz Mountain Industries
Country / Region United States
Age 84
Industry Real Estate
View net worth over:   Max 1 year 1 quarter 1 month 1 week

Relative Value

Leonard Stern's net worth of $6.77B 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:

The majority of Stern's fortune is derived from closely held Hartz Mountain Industries, which owns more than 260 buildings totaling more than 45 million square feet in New York, New Jersey and across the U.S., according to the company's website. Each property has been individually valued. Occupancy rates, rent per square foot and cap rates for Stern's real estate were aggregated using data from Bloomberg, Real Capital Analytics and REIS. The analysis assumes the properties are about 50% leveraged.

Stern's largest concentration of properties is in northern New Jersey, where he owns an industrial portfolio totalling more than 19 million square feet. He also owns the Tribeca Grand and Soho Grand hotels in Manhattan.

The billionaire sold the family pet care business to private equity investor John Childs in 2000.

Gus Milano, president of Hartz Mountain Industries, didn't respond to requests for comment on the net worth calculation.


Family: Married, 3 children

Father Max Stern immigrated to the U.S. from Fulda, Germany, in 1926. He made the passage accompanied by 5,000 singing canaries that he'd received from a friend who couldn't pay back a loan. Stern had become the largest livestock importer in the U.S. by 1934, manufacturing packaged bird foods under the Hartz Mountain brand.

Leonard Stern joined his father's pet food business after graduating with an MBA from New York University in 1959. He expanded into real estate development in the 1960s, acquiring two tracts of barren marshes totaling over 1,250 acres in New Jersey's Meadowlands, six miles from downtown Manhattan. His real estate assets had grown to more than 35 million square feet by the late 1980s. At the same time, Hartz Mountain branched into publishing and the carpet cleaning business.

Stern's sons, Emanuel and Edward, joined their father's business in 1990, expanding the company's real estate holdings with the Soho and Tribeca Grand hotels in New York. He sold the pet-care products business to private equity mogul John Childs in 2000.

The billionaire has three children from his first marriage.

  • 1926 Father, Max Stern, immigrates to the U.S. from Germany.
  • 1934 Max starts producing packaged bird food under Hartz Mountain name.
  • 1938 Leonard Norman Stern is born in New York to Max and Hilda Stern.
  • 1959 Buys out his siblings and joins his father's pet food business.
  • 1969 Expands into real estate by acquiring 1,250 acres in New Jersey.
  • 1980 Enters cleaning business by buying Carpet Magic Co.
  • 1990 Sons Emanuel and Edward join the family business.
  • 1996 Builds Soho Grand and Tribeca Grand Hotels.
  • 2000 Sells pet care and publishing operations for about $500 million.
  • 2010 Starts investing in oil and gas.