(Bloomberg) -- A Rolex watch designed for spelunking and several models of the Patek Philippe Nautilus led declines in the Bloomberg Subdial Watch Index over the last month.

The index, which tracks prices for the 50 most-traded watches by value on the secondary market, declined by 1.4% over the past 30 days, according to data provided by Subdial, a UK-based platform for selling and trading pre-owned watches. 

The Rolex Explorer II, with the reference number 216570, was the biggest decliner, falling 3.4% in a month to an average price of $9,875. The watch features a GMT hand and a fixed 24-hour bezel that indicates whether it’s day or night. 

The Patek Nautilus 5711/1A-010 with a blue dial fell by 2.9% over the same period to $102,333. The Patek Nautilus Travel Time 5990, which allows users to track a second time zone, lost 2.7%, with an average price of $130,882. 

Prices for pre-owned watches have fallen by about 26% in a year, the Bloomberg Subdial Index shows. Values surged during the pandemic in 2021 and into 2022, particularly for Patek, Rolex and Audemars Piguet timepieces.

The Rolex Datejust 16233, a 36-millimeter diameter watch in two-tone gold and steel, was the best performer during the month, climbing 3.3% to an average price of $6,396. 

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