Gelbaum, who reads the Spanish-language newspaper La Opinion and is married to a Mexican American, said his views on immigration were shaped long ago by his grandfather, Abraham, a watchmaker who had come to America to escape persecution of Jews in Ukraine before World War I.
"I asked, 'Abe, what do you think about all of these Mexicans coming here?' " Gelbaum said. "Abe didn't speak English that well. He said, 'I came here. How can I tell them not to come?'
"I cannot support an organization that is anti-immigration. It would dishonor the memory of my grandparents."
Born in Minneapolis, the second of four sons, Gelbaum moved to California when his father, Bernard Gelbaum, became founding chairman of the UC Irvine math department.
David Gelbaum showed early prowess in math, taking calculus at UC Irvine while still in high school. Months before he graduated from UCI in 1972, he was hired by math professor Edward O. Thorp to help with a business that needed a math researcher.
Thorp, who wrote the book "Beat the Dealer," about how to count cards and win at blackjack, was applying mathematical wizardry to the largest crap game in the world: Wall Street.
His formulas, which later appeared in his book "Beat the Market," led him to launch the nation's first market-neutral hedge fund -- one intended to make money for investors whether the market goes up or down. From 1970 to 1989, the fund never had a losing quarter and increased investors' money more than 13-fold.
Gelbaum was one of his first math researchers hired to track and exploit the price discrepancies between a company's stocks and its options, warrants and convertible bonds.
"He was smart. He was idiosyncratic. He was always looking for more," Thorp said.
Thorp recalls a conversation with young Gelbaum about his salary.
"I said, 'I think we can multiply your salary by five times in five years.' He came back to me five years later with the same question. I said, 'I think I can multiply your salary by five times in five years. But I don't think I'll be able to do that again.'"
The firm, called Princeton-Newport Partners, was dissolved in 1989, when five of the firm's stock brokers based in Princeton, N.J., were convicted of scheming to create illegitimate tax losses. The convictions were overturned on appeal. Neither Thorp nor Gelbaum was implicated in the scandal.
