"The way of doing business has changed," she said. "It's much more competitive, much more knives-in-the-back."
Guests at Bergman's midtown Manhattan apartment, where she's lived for more than 60 years, may be invited to sip a vodka or scotch, while seated on furniture crafted in Europe before World War II. The French Louis XV chairs are off-limits.
Four personal assistants attend to her needs around the clock, and she calls on colleagues at New York-based Stralem including chairman Hirschel Abelson when she needs research on particular securities. While she never married and doesn't have children, she does own a Maltese named Fanny.
Her career was a near-realisation of a dream she had as a teenager. In an essay at the time, she wrote that she wanted to follow her father, a private banker, on to the Berlin Stock Exchange. He made that world seem so "lively", she said. She would have been the first woman to attain that position.
Those aspirations stalled when the Nazis chased her Jewish family from Germany and then Holland. They came to the US. In 1942, Bergman began working as a secretary at a bank. Fifteen years later, she joined Hallgarten & Co, a member of the New York Stock Exchange.
"Women on Wall Street were not very popular," she said. She would join Loeb Rhoades & Co, and in 1973, Stralem, where she finally felt like she belonged. "This was the first place where I was treated like an equal."
Stralem oversees almost US$2 billion ($2.8 billion) in assets and runs a strategy focused on identifying "up-market" and "down-market" stocks. It manages money for institutions and individual accounts, 11 of which are Bergman's. She serves on its investment committee.
Bergman, who stopped visiting the office in December and turns 100 in August, attributed her longevity to good genes, not any special diet. She said she stayed fit by riding dressage horses until she was 80 and mentally sharp by forgoing retirement.
"She's been through multiple business cycles, ups and downs, recessions, depressions, and has a good feeling for where things are going," said George Falk, a doctor of internal medicine in private practice in Manhattan. "I have a great deal of trust in her."
Her family's post-war experience informs her advice today. Because it took a decade after coming to New York for Bergman to recover her family's wealth, which was frozen by US and Dutch authorities, she emphasises the importance of safeguarding funds.
One bright spot for today's investor is the ability to sell large blocks of stock quickly, Bergman said. Years ago, it would have taken Stralem weeks to execute a large order. Now it takes hours or days.
At the same time, speed has "great disadvantages", she said.
"People trade who shouldn't be, or they do something too fast."
Her caution has translated into loyal clients, according to Philippe Labaune, head of trading at Stralem, who said that in almost 20 years at the firm, he's never seen her lose an account. Though some did close when their owners died.
"In this business, you have to get the confidence of your clients," Bergman said. "You don't have your clients for three weeks, you have them for at least three years. It takes that long to know if you're doing a good job."
Customers appreciate that she has her own wealth. "They had the feeling that I didn't need to churn their accounts because I had money myself," she said.
Bergman does recall one investment she let slip away - Apple.
"I missed Apple totally," she said. "Apple was too much for me."
That brings her to another tip - make your own decisions. "I always like to do what I want to do, then it's my fault," she said. "I can't blame anyone else."
Irene Bergman
• Turns 100 years of age in August.
• Financial adviser at Stralem & Co.
• Family fled Nazi Germany to the US.
• In 1942, began working as a secretary at a bank.
• Fifteen years later joined NYSE member Hallgarten & Co.
• Joined Loeb Rhoades & Co, and in 1973, Stralem.
