Rolex Datejust 31
+42 % above RRP
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ℹ️ 1-month trend
Price change over the past 30 days. Shows the short-term market movement — relevant if you want to buy or sell soon.
ℹ️ 4-month trend
The central metric behind the momentum score. It filters out short-term swings and shows the true, medium-term market trend of this reference.
ℹ️ Volatility
Annualised price fluctuation. Below 10 % = very stable, 10–20 % = normal, above 20 % = volatile. With high volatility the price can change quickly — in both directions. Be cautious about buying without checking the current price.
ℹ️ Momentum score
ChronoCheck's own indicator from 0 to 100, calculated from the 4-month trend, volatility and market direction.
- Above 60 — Upward trend. Good time to sell, prices are rising.
- 40 – 60 — Neutral. Stable price level, no pressure to act.
- Below 40 — Downward trend. Wait or enter at a good price.
ℹ️ Investment Grade A/B/C/D
ChronoCheck's own rating for each reference. A 0–100 point scale, made up of four weighted components:
- Momentum (40 pts) — trend strength from the momentum score.
- Liquidity (25 pts) — number of active live listings.
- Stability (20 pts) — inverse volatility — the calmer, the better.
- Source robustness (15 pts) — number of independent market sources.
- A · 75+ Trend is right, liquidity good, data broad.
- B · 55–74 Solid, but one component weaker.
- C · 35–54 Average, volatility or market breadth weigh on it.
- D · below 35 Downward or too little data — a collector's piece.
Not investment advice. Pure data analysis from aggregated market sources.
What if you had bought back then …
What would a purchase at the median market price back then have become — at today's level of $7,532. A pure return calculation, excluding insurance, servicing and transaction costs.
Data from an aggregated median time series (watch_market_daily). CAGR = Compound Annual Growth Rate, normalized to 365 days. Not an investment recommendation.
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Technical data
Lift angle 52° — important for timing-machine diagnosis: with this value a watchmaker can correctly measure rate deviation, amplitude and beat error. ChronoCheck verifies such technical details directly from the manufacturers' factory specifications.
Rolex Ref. 178240 — Variants and collector names
Known as: DJ31 Steel, Midsize Datejust, Lady 31, DJ 31 Smooth
Production phases and changes
- 2000: Ref. 178240 replaces Ref. 78240
- 2004: Facelift: sturdier bracelet construction, polished lugs, engraved rehaut
- 2018: Introduction of successor Ref. 278240 with Cal. 2236 (Syloxi hairspring, 55h power reserve)
- 2022: Discontinuation of Ref. 178240 (steel)
Bezel variants
- Smooth Steel Bezel "Plain Bezel / Smooth Bezel"
Dial variants
- Black Concentric Arabic — DATEJUST – concentric groove structure, Arabic numerals
- Black Stick — DATEJUST / OYSTER PERPETUAL – stick hour indices, applied white gold indices
- Blue Stick / Blue Sunburst Index — DATEJUST – stick indices, WG appliqués
- Blue Roman — DATEJUST – Roman numerals, WG appliqués
- Pink Stick — DATEJUST – stick indices, WG appliqués
- Pink Roman — DATEJUST – Roman numerals, WG appliqués
- Floral Motif / Rhodium Flowers — DATEJUST – embossed floral motif, no standard indices, single Arabic numeral at 6 o'clock
- Silver Concentric Arabic — DATEJUST – concentric groove structure, Arabic numerals
- Silver Stick — DATEJUST / OYSTER PERPETUAL / Swiss Made – stick hour indices, applied white gold indices
- Slate Floral — DATEJUST – floral pattern dial, Arabic numeral at 6 o'clock, date at 3 o'clock
- White Stick — DATEJUST – stick indices, WG appliqués
- White Roman — DATEJUST – Roman numerals, WG appliqués
Crystal variants
- Saphirglas mit Cyclops
Bracelet variants
- Oyster Solid Ref. 78350
- Jubilee Ref. 63160
Serial numbers
- A-Serie (~ca. 3.0M) – ca. 9.9M (Random Serial) (2000–2010) — Rolex switched to the randomized serial number system from around 2010. Serial number engraved in the rehaut at 6 o'clock (from around 2007/2008, engraved rehaut including serial number in the serial ring). Before 2007: serial number between the lugs at 6 o'clock, under the bracelet.
- Random (8-stellig) – Random (8-stellig) (2010–2022) — From around 2010/2011, Rolex introduced the randomized serial number system. No reliable year assignment via the number alone is possible anymore. Serial number engraved in the rehaut.
Brand profile: Rolex
Rolex is the most counterfeited watch brand in the world. Super-clones (VSF, ARF, Clean — the latter inactive after a raid in 07/2025, only old stock remaining) achieve 95%+ similarity. Authenticity is almost always detectable only via micro-details + movement behavior.
- Case back: ALWAYS solid and closed — any display window = definitely fake (exception: Vintage Ref. 6085 only)
- Minute hand length: genuine Rolex minute hands end EXACTLY at the minute chapter ring. 1 mm too long = fake. Strongest VSF tell.
- Seconds hand: smooth sweep without any hesitation — the slightest tick = fake
- Cyclops lens (on date models): must magnify exactly 2.5×, date fills almost the entire window
Serial number format: Since 2010: random alphanumeric combination (e.g. 'G3M9K721'). 2000–2010: letter + 6–7 digits. Serial number engraved on the rehaut at 6 o'clock (from ~2005). Older models: between the lugs at 6 o'clock on the case.
Further sources
Buying guide: Rolex Datejust 31
Entry into Rolex
At $7,532 this reference is one of the more affordable ways to wear a Rolex on your wrist. That is precisely why many pieces have already passed through several hands — condition varies accordingly. Buyers here should pay particular attention to service history and honest photos from the seller.
Where the price stands
The price has fallen by -5.8% over the past four months. No crash, but a clear downward trend. Buyers currently have room to negotiate; sellers are better off waiting for the market to bottom out — unless they have to sell.
Watch out for swings: This reference has an above-average volatility of 53.4 percent. In concrete terms: the price can move by several hundred euros within a few weeks. Check the current value before buying or selling — old listings or auction results from two months ago are of little help.
What to look out for when buying?
- Authenticity: The serial number and reference on the case must match the papers. A professional authenticity check of the Rolex Datejust 31 reliably rules out counterfeits.
- Condition: Check scratches on the case and bezel — professional refurbishment can leave traces.
- Service history: A documented service by the manufacturer or a certified watchmaker increases the value.
- Scope of delivery: Box, papers and warranty card make a noticeable price difference on the Datejust 31.
- Independent certification: The CPS-52 standard covers 52 checkpoints — from the serial number and the timing machine to water resistance. The result is secured on the blockchain and can be verified at any time.
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