Jeff Koons, Hanging Heart (Magenta/Gold)

At Sotheby's Nov. 14 sale, dealer Larry Gagosian, who represents Koons, bid this huge stainless steel sculpture up to $21 million (not including commission), setting a price record for a living artist at auction. Sold by real estate investor Adam Lindemann, it was estimated at $15 million to $20 million.

Francis Bacon, Second Version of Study for Bullfight No. 1 (1969)

Sold by Germany's Langen Foundation, this piece was the most expensive work sold this season in New York. On Nov. 14 at Sotheby's, it went for $45.9 million to art dealer Philippe Segalot, against an estimate of upwards of $30 million.

Andy Warhol, Liz

Hugh Grant bought this 1963 portrait of Elizabeth Taylor by Andy Warhol six years ago for $3.6 million. Christie's had it estimated at $25 million to $35 million at its Nov. 13 sale. It sold for $21 million, with Christie's commission bringing it to $23.5 million. The auction house says Grant is pouring some of the money back into works by younger artists.

Gerhard Richter, Jet Fighter

Several bidders chased his giant painting from 1963, but its record price of $11.2 million was still just a bit above its $10 million low estimate. It sold at Christie's on Nov. 13.

Jeff Koons, Diamond (Blue)

New York art dealer Larry Gagosian was the winner for this gleaming giant steel gem, which sold for $11.8 million at Christie's. The price set a record for the artist, more than doubling his previous record, but it had been expected to rise as high as $20 million. Still, a new standard was set for Koons the next day.

Mark Rothko, Untitled (Red, Blue, Orange)

The top seller at Christie’s was a large abstract, which brought $34.2 million against an estimate of $25 million to $30 million at Christie's. Christie’s had marketed the painting aggressively to Russian collectors, as Rothko was born in Belarus.

Vincent van Gogh, The Fields (Wheat Fields)

The painting hung over the artist's bed at the time of his death and came with a presale estimate of $28 million to $35 million. It went unsold at Sotheby's on Nov. 7, but C.E.O. Bill Ruprecht says that, as the company had guaranteed it, he’s happy to have it.

Pablo Picasso, La Lampe

Offered up by the artist’s family at a hoped-for $20 million, this portrait also failed to sell at Sotheby's.

Paul Gauguin, Te Poipoi

The top purchase of Sotheby's Nov. 7 auction went to Hong Kong real estate investor Joseph Lau, who paid $39.2 million for this Tahitian scene. The low estimate was $40 million.

Amedeo Modigliani, Portrait du sculpteur Oscar Miestchaninoff

This painting of a Russian sculptor sold for $30.8 million against a high estimate of $25 million at Christie's on Nov. 6.