These two works have more in common than just being vibrant, colorful and disturbing depictions of the human head. They are both works unmistakably identifiable as by Jean-Michel Basquiat and Pablo Picasso respectively. Both are strong works that may appeal more to connoisseurs than trophy hunters. And both will be auctioned in London these next two weeks.

Both works are also very clearly distressed sales since they were bought a week apart in New York in the Autumn of 2013. Sure, works of art come back to the auction block quickly … sometimes. But that’s usually during a rising market and times of economic optimism.

No one would use those words to describe today’s climate. The world is reeling from a variety of destabilizing economic forces and volatile markets. The near universal opinion is that the art market is pulling in its horns and getting ready for a retrenchment.

Then, there’s the issue of the estimates. The Picasso made $39.9m in New York with fees. It’s on offer this week with a low estimate of £16m. If the work sells at the low estimate, the dollar price will be about $28.8m with fees. So the seller is willing to take a hit of more than $10m just to get back some of the money they have sunk into the portrait of Marie-Therese Walter.

The Basquiat made $12m that November. It was a bold, record-setting price for a work on paper coming six months after two similar works depicting large figures each made $5m. Since that time, several more sales were made in that range, including one in May of last year that finally took the crown for $13.6m.

Few Basquiat experts think the market for these kinds of works on paper is still rising. The seller clearly isn’t counting on that either. The London low estimate of £4.5m would net the seller a little more than half of what was paid 2+ years ago.

Whatever is driving either or both sales, validated works with low estimates have a tendency to attract bidders. Once bidders are engaged, there’s no telling where they will decide to stop. Which means both of these works are well worth watching as bellwethers of the current market. Strong bidding would bespeak confidence in the art market; liquidation prices or a failure to sell would obviously not.

Pablo Picasso | Sotheby’s

Jean-Michel Basquiat | Sotheby’s