Week 15, 2026

The most striking thing about week 15 isn't the inventory build or the price slide in isolation. It's both happening at once, with force. Active listings jumped 6.56% week on week to 27.25 million stones, new listings surged 35.7% to 2.41 million, and yet the median price per carat fell to $982.93, a seven-week low, down from $1,020 the prior week and from $1,174 back in W09. More supply, lower prices. The direction is consistent and it's been consistent for nearly two months.

Lab-grown is doing most of the driving. At 65.9% of active inventory, lab-grown share has hit a fresh seven-week high, up from 60.1% in W09. The listing flow tells the same story: 1.84 million new lab-grown listings came to market this week against just 570,000 natural. Lab-grown's median new-listing price did tick up to $856 (from $723 in W14, an 18.4% move), but that's a compositional shift worth watching rather than celebrating. When the natural side is pulling back and lab-grown volume surges, the mix alone can move medians. Natural's per-carat price actually nudged up slightly to $2,330.65 versus $2,280 prior, so naturals aren't getting cheaper. The overall market is just becoming more lab-grown by the week.

The off-market collapse is genuinely significant context. W14 saw nearly 3.9 million listings pulled, which was the anomaly. This week's 833,710 is a return to something closer to normal churn. Combined with the new-listing surge, active inventory is up 29% across the seven-week window and the median carat weight of active stones hit a new high at 1.35ct. The market is getting larger and heavier at the same time prices are drifting down. The $89.1 billion total inventory value reflects scale, not strength.

Shape movers were loud this week. Princess cut posted a 71% jump in median new-listing price to $998.75, and emerald cut climbed 45.9% to $1,218. Both moves are worth watching but both come on volume that's modest relative to the broader market, so I wouldn't call them signals of a demand shift just yet. Ovals went the other way hard, median new-listing price down 23.5% to $900 on 446,000 new listings, the second-highest new-listing volume of any shape this week. Round maintained its dominance at 40.3% of new listings with a median of $839. The spread between ovals and rounds has effectively collapsed for the moment, which is a notable reversal from the premium ovals have carried for the past couple of years.

The cross-retailer overlap at 47.3% and the price spread at 89.9% are both flat. Roughly half of all stones appear across more than one retailer, and where they do, the gap between cheapest and most expensive listing sits just under 90%. That spread is a buyer's edge. A 1.35ct stone at the median sits somewhere around the $1,094 marker, but the same stone listed by multiple retailers could swing nearly 90% in price between the cheapest and dearest option. Comparison shopping isn't a nice-to-have right now. It's where the value is.

Going into W16, the question is whether the new-listing surge moderates or whether supply continues to outpace any demand recovery. Lab-grown's share at a seven-week high and the per-carat price at a seven-week low is a combination that tends to compound. If natural listing volumes don't recover and lab-grown keeps flooding in at this rate, the median price floor will keep testing lower. Buyers with flexibility on origin and shape are in a strong position right now. Those holding out for specific naturals will find the market less accommodating.

Lucy Market Index

Ten numbers I record every snapshot.

Versus Week 14, 2026

Biggest shape movers

Recent trends

How metrics are tracking across the recent window of snapshots.

How the Lucy Market Index has moved

By origin

Top shapes by new listings

Notable stones

Each stone links to its full Carat Hunter listing.