Irving Kahn, who made his first stock trade in June 1929 — turning a tidy profit from the stock market crash four months later — and persevered for more than eight decades to become Wall Street’s oldest living active professional investor, died on Tuesday at his home in Manhattan. He was 109.
His son Thomas confirmed his death.
A disciple and later partner of Benjamin Graham, the contrarian advocate of “value investing,” Mr. Kahn would go on to work at Abraham & Company and Lehman Brothers, which he left in 1978 to open Kahn Brothers Group with two of his sons, Alan and Thomas. When he died, he was chairman of Kahn Brothers, a privately owned investment advisory and brokerage firm, which manages $1 billion through its subsidiaries.
He was also the last surviving member of what had been described as the oldest living sibling quartet. One sister, Lee, died in 2005 at the age of 101. Another sister, Helen Reichert, was seven weeks shy of her 110th birthday when she died in 2011. Their younger brother, Peter Keane, died last year after turning 103.
Until late last year, Mr. Kahn was still commuting by taxi to his Midtown office from his Upper East Side apartment three days a week.
Irving Kahn was born in Manhattan on Dec. 19, 1905 (the stock market rebounded that day), to Mamie Friedman and Saul Kahn. His father sold light fixtures.
Irving graduated from DeWitt Clinton High School and enrolled in City College, but quit after two years to become a clerk at Kuhn, Loeb & Company. He immediately made a beeline for Ben Graham, a trader at the Cotton Exchange with a reputation for outperforming the market.
Mr. Graham recruited Mr. Kahn to be a part-time teaching assistant at Columbia Business School, where Mr. Graham taught after trading hours. His acolytes included Warren Buffett. Both Mr. Kahn and Mr. Buffett were so taken with him that they bestowed the middle name Graham on their sons.
At Columbia, Mr. Kahn also met Ruth Perl, who was studying for her doctorate in psychology. They married in 1931. She died in 1996. Beside his sons Thomas and Alan, he is survived by seven grandchildren and eight great-grandchildren.
In reviewing a biography of Mr. Graham, The Economist magazine wrote in 2012 that he had “developed the concept of a ‘margin of safety,’ ” urging investors “to buy shares well below the company’s intrinsic value.”
Already steeped in that concept, Mr. Kahn expected a market downturn in 1929 because traders were bidding stock prices into the stratosphere.
He sold short 50 shares of red-hot Magma Copper that June, wagering that the price would plummet. When the market crashed on Oct. 29, his $300 investment, about $4,000 in today’s dollars, more than doubled.
“I wasn’t smart,” Mr. Kahn recalled in a 2006 interview with National Public Radio, “but even a dumb young kid could see these guys were gambling. They were all borrowing money and having a good time and being right for a few months and, after that, you know what happened.”
Mr. Kahn was in the first pool of applicants to take the Chartered Financial Analyst exam and was a founding member of the New York Society of Security Analysts.
After the 2008 financial crisis, he endorsed a division between banks that accept deposits and those that use their own money to trade securities.
Mr. Kahn meticulously studied a company’s performance, measuring its potential return not by the quarter but over four or five years. In 2012, though, he told Bloomberg Businessweek that while Mr. Graham’s principles still applied, they were often overlooked in today’s babble.
“So many people watch financial TV at bars, in the barber shop,” he said. “This superfluity of information, all this static in the air.”
Mr. Kahn continued to devour newspapers and magazines until a few hours before he died. His grandson Andrew, a research analyst at his grandfather’s firm, had been reading an Economist cover article to him on Vladimir Putin.
Thomas Kahn, who is 72 and president of Kahn Brothers Group, said that studies of centenarians, including his father, by Dr. Nir Barzilai at the Institute for Aging Research at the Albert Einstein College of Medicine in the Bronx conclude that the secret to longevity is a mix of DNA, healthy living and luck.
“My father smoked until he was 50, and he didn’t watch what he ate,” Thomas Kahn said. “So the preponderance of his case was DNA and luck.”
He said he received an email from Dr. Barzilai the other day suggesting that his father will remain forever young. “Irving’s not dead,” the doctor said, “because we have his cells and his DNA, and they’re working every day in our laboratory.”