Two data points landed on the diamond side this month, and for the first time in over a year they pointed the same direction. On September 2 the 1-carat RapNet Diamond Index, the RAPI, posted its first increase in 15 months. A week later Signet Jewelers, the largest specialty jeweler in the United States, reported a second-quarter profit of $2.19 a share against a $1.74 consensus and raised its full-year guidance. Wholesale and retail turned up together.

The RAPI turn

The 1-carat RAPI had fallen for 15 consecutive months before September 2. That is the context that makes a single positive print worth reporting. The index tracks asking prices for the most liquid natural category on RapNet, and its decline had been the cleanest measure of the natural diamond downturn. One increase does not reverse 15 months of erosion, and Rapaport itself has been careful not to call a bottom on the strength of a single reading. But the direction changed, and the trade has waited more than a year for that.

The mechanics behind the turn favor patience over enthusiasm. RapNet asking prices adjust as dealers reprice lists, and a single monthly uptick can reflect thinner supply of well-cut goods as much as stronger bids. The distinction matters because a supply-driven firming behaves differently from a demand-driven one. The trade will only know which it is watching once transaction data and the next monthly index catch up to the September print.

The turn is narrow so far. It is the 1-carat pointer specifically, not a broad move across every size and color, and asking prices are not the same as closed transactions. What the increase does confirm is that the relentless downward pressure that defined the natural market since mid-2025 eased in the most watched category. Whether smaller and larger goods follow is the question dealers will track through the fall selling season.

Signet reads the retail counter

Signet is the closest thing the trade has to a public read on the American bridal counter. Its second-quarter EPS of $2.19 cleared the $1.74 estimate by a wide margin, and the beat came with a guidance raise rather than a maintained outlook. The company lifted its fiscal 2027 adjusted EPS range to $10.45 to $12.15, up from a prior $9.20 to $11. The new floor of $10.45 sits within the old range, and the new ceiling of $12.15 moves the top up more than a dollar.

It is worth keeping the sample size honest. Signet operates a national footprint of banners and runs its own promotional cadence, so its quarter reflects execution as much as end demand. One retailer, however large, is not the whole American market, and the independents that make up the bulk of the specialty channel do not report on the same calendar. What Signet does provide is a timely, audited read, and that read said the mid-market bridal shopper spent more freely this summer than the guidance set at the start of the year assumed.

The structure of the guidance matters as much as the numbers. A retailer can manufacture a single strong quarter by pulling back on promotions and accepting lower traffic, but that kind of beat does not support a raised full-year outlook. Lifting guidance signals that management expects demand to hold into the back half, which contains the holiday quarter that decides the year for most jewelers. The market read it that way, sending the shares up about 20% on the day of the report.

The lab-grown wrinkle

A word of caution the headline numbers hide. Signet sells both natural and lab-grown diamonds, and the RAPI measures natural asking prices only. A firmer natural bid and a strong bridal quarter can coexist with continued lab-grown price deflation at retail, and the two trends have moved on separate tracks for most of the past two years. A single company beat and a single index print do not settle how that mix is shifting. What they establish is that the natural index stopped falling and the largest specialty jeweler saw enough demand to raise its year.

What the two prints add up to

Taken together, the RAPI turn and the Signet raise describe a natural diamond market that found demand at the counter and a floor at wholesale in the same stretch. That is a more coherent picture than the trade has had since 2025, when retail softness and index declines fed each other. It is not a recovery yet. It is two prints, one from an index and one from a single retailer, that stopped confirming the bear case. The Swiss watch figures moved the same way this month, a shift I noted in the watch report, and the broader read across the trade is in the weekly wrap. The number the diamond desk will watch next is the October RAPI. One increase is a data point. Two in a row would be a trend.