5 secrets of the modern art market – new BBC documentary reveals how auction houses really make their money

“Old brown furniture doesn’t sell as well as it used to,” says film-maker Michael Waldman, who spent nine months filming behind the scenes at Christie’s, watching oligarchs and hedge-fund owners spending their millions.

“Now, when there’s so much new money being made, people come into the art market who have not grown up with ‘old art’ and they quite often go for stuff that fits their lifestyle. You can celebrate this, but also regret that to some extent it’s a world of hype.”

So what are the secrets from these rooms where fortunes are spent at the strike of a hammer?

1. Five “bad” Rembrandts equal one Jeff Koons

Jeff Koons’s basketball suspended in water, One Ball Total Equilibrium Tank (below), sold in May at Christie’s New York for the equivalent of £12.3 million.

“What is slightly bizarre,” says Waldman, “is that you could get at least five ‘bad’ Rembrandts for that, let alone something going further back in time.” Rembrandt’s Man with a Sword portrait, for example, sold in 2013 for £2.2 million.

“I think to be an artist now must be difficult,” Waldman says. “If you’re painting away and doing good stuff, and you see what a Koons goes for, would you think, ‘I should be doing something different in order to attract the eye of hedge-fund investors who like that sort of thing’?

“It is a worrying matter, that contemporary art now goes for such crazy prices, but equally, it’s a magnificent one. At least people are taking it seriously.”

2. How To Get More Monet For Your Money

While an intricate, dreamy townscape by impressionist master Claude Monet might be lovely to look at, the art market pays bigger bucks for works by the artist that feature water.

“I raised my eyebrows when the art advisor told me this,” says Waldman. But the evidence bears this out: Monet’s oil painting of a waterlily pond, Le bassin aux nymphéas, sold for £40.9 million, while his haystacks (Les meules à Giverny, below) sold for £13.2 million and a field of flowers (Iris mauves) went for £10.8 million.

“Water lilies, the Seine scenes, reflections,” says Waldman, “that’s what people think about Monet. When you have a townscape, the market is much less. So with a townscape, you can get more Monet for your money because it’s cheaper than it would be if it was of a river.”

3. How to make £42 million from art

Investing in art can reap hefty financial rewards quickly. In 2004 art collector Adam Lindemann bought an untitled 8ft painting by Jean-Michel Basquiat (below) for around £3m; he sold it for £45 million in May this year.

It was bought by a 40-year-old Japanese businessman, Yusaku Maezawa, founder of the online fashion retailer Zozotown, paying a record amount for the artist, who died in 1988.

“Art advisors often help with a purchase like this,” says Waldman. “Clients pay them to say, ‘I think you should go for this. That price is a good one. If you want, I will fly from San Francisco to London to bid for this Monet for you.’ ”

Lindemann told Waldman that art can be an investment, but buyers better love the painting – because art can go up and down and you could end up with no profit at all.

4. Rubens is the master of old masters

Being trumped by a higher bidder isn’t just a crushing disappointment – it can be something of a relief, too.

While filming, Waldman witnessed the moment that Peter Paul Rubens’s masterpiece Lot and his Daughters was sold for £44.8 million, the highest price ever paid for an Old Master at Christie’s.

The underbidder, whose offer of £39 million was blown out of the water, said, “In a way, I’m millions of pounds richer, but I also feel empty and bereft because I haven’t got the thing that excited me enough to bid that much for it.”

The most expensive Old Master ever sold is also a Rubens. The Massacre of the Innocents went for £49.5 million at Sotheby’s London in 2002.

5. When a bid isn’t a bid

During a sale, you may see an auctioneer nodding and waving his arms to take bids at the start – but sometimes he’s not actually got any bids at all.

What’s known as “chandelier bidding” is just a way to get the bids up to the reserve price (the lowest price the seller will accept).

Once the bid is high enough, he has to find a real seller quickly or declare the piece “unsold”.

Sold! Inside the World's Biggest Auction House is on 9.10pm tonight, BBC2