Equal parts connoisseur and razor-sharp businessman, Robert Mnuchin rose to the highest ranks of the financial industry before becoming one of the world’s top dealers in modern and contemporary art. Until 1990 he was a partner and the head of equity trading at Goldman Sachs and, during part of that time, served as a director of the American Stock Exchange and the chairman of the Upstairs Trading Com­mittee of the New York Stock Exchange. After more than 30 years, Mnuchin left Wall Street to partner with the dealer James Corcoran in C&M Arts on Manhattan’s Upper East Side. The space was renamed L&M Arts in 2005, when the private dealer Dominique Levy replaced Corcoran, who had left long before. There, Mnuchin has sold blue-chip postwar artworks and organized museum-quality exhibitions—“Jackson Pollock: Drip Paintings on Paper 1948–1949,” “Picasso: The Classical Period” and “Yves Klein: A Career Survey,” to name just a few—that marry loans from institutions and private collections with choice pieces for sale. Next year, he and Levy will open an outpost in Los Angeles concentrating on contemporary artists. In the following conversation, Mnuchin draws parallels between equities trading and art dealing, frequently putting the interview on hold to take calls while offering this gracious apology: “It’s a habit from my Wall Street days—I had a phone with 120 lines. My boss would stand behind me and say, ‘Damn it, pick up the blinking lights!’ ”

You’re a major player at the auctions. At some sales I’ve attended, you’ve bought upwards of four items.

Were you there at my favorite night, when I waved my white scarf?  

Oh yes, I remember that well. You waved it in surrender upon dropping out of the bidding war for Joseph Cornell’s Medici Princess box at $2.3 million. [The work sold for $2.6 million.] An amusing moment!

I try to make it fun. As so many of the prices have become so high, it has understandably gotten more serious. But it’s still great. I love going to auctions. All the people in the room love it too—otherwise they would just call in their bids.   

There’s also the competition for an object. As a trader, you once quipped, “The worst trades are generally when people freeze and start to pray and hope, rather than take some action.” Is that observation relevant to the art market, as well?

Yes, it applies anytime you are buying and selling anything or making decisions of any kind, in business or in life. You might have a high batting average, but you are going to make mistakes. And it certainly is useful, with the investor part of one’s brain, to recognize a mistake—don’t try to defend it, but say, “Let’s get out,” and move on to something else.

So what is L&M’s approach? Tell me a bit about pricing.

For us to pre­­sent something, we have to like and respect it. It isn’t just an object for us to sell and make 10 or 15 percent off of. The second part is, we have to respect the price. Sometimes you’ll see auction houses offer very low estimates or very high estimates. I’m a great fan of auction houses, but they don’t feel a sense of responsibility for the price. We do. We try to set fair and appropriate prices based on the artist and the quality of the work in question and on the current marketplace. We’re proud of that. I don’t know how much we give up in keeping our standards enormously high, as opposed to being driven by the opportunity to make money.   

Aren’t auction houses’ estimates a way of creating a psychological expectation for what an object is worth?

Well, there are two ways of looking at that. One is that a low estimate could attract greater interest, and the hope is that once people start bidding, they will keep bidding, whereas a high estimate can scare people off. Or a high estimate can create a frame of value. There’s a case to be made on both sides. But I think most things are well served by lower estimates.