The tycoon who loved women so much he spent $700m on them

It is a question the art world has pondered for years: what paintings does Wall Street's "hedge-fund kingpin" like to hang on his walls? Those who have speculated about Steve Cohen's closely guarded collection have never got very far; the US billionaire buys secretly and swiftly, often from private hands.

Now, however, the secret is out. Mr Cohen, America's 36th-richest man, has been amassing pictures of women at his $15m mansion. They are, of course, no ordinary women but 20 portraits by some of the 19th and 20th century's most famous artists. The list includes Andy Warhol's Turquoise Marilyn, Vincent Van Gogh's Portrait Of A Peasant Girl and Edvard Munch's Madonna. The works will form a dedicated exhibition – "Women" – at Sotheby's in New York from 2 April.

While some were bought privately for undisclosed sums, the auction prices of others hint at the lengths to which Mr Cohen will go to acquire a painting he likes. In 2005, he paid $11.5m, a record at the time for Munch, for his Madonna; a year later, he snapped up Willem De Kooning's Woman III for $137.5m. He brokered a deal to buy Warhol's turquoise silkscreen print of Monroe for $80m, while Picasso's 1932 work Le Repos, which seems to depict both the Spanish painter's wife, Olga, and his young lover, Marie-Thérèse Walter, cost Mr Cohen $34.7m in 2006.

The public has never had a chance to view Mr Cohen's famed collection, which he and his wife, Alexandra, have amassed over the past decade. The idea for displaying the works – none of which are for sale – came from William Ruprecht, president of Sotheby's, and Tobias Meyer, the auction house's director of contemporary art, when they visited the Cohens for dinner.

Speaking to The New York Times, Mr Cohen said: "I was game. It is unlikely that a museum would do something like this and I figured, 'Why not let the public see the pictures?' It's a free exhibition."

Although he only began collecting art in 2000, Mr Cohen took quickly to his hobby, appearing in Forbes magazine's list of "top billionaire art collectors" in 2005. He is believed to have spent about $700m on pictures so far. In 2003, it was reported he had spent 20 per cent of his income at art sales.

He is said to be building a private museum for some of his favourites at his home in Greenwich, Connecticut.