March 2026

The number that stopped me cold in March wasn't the inventory surge or the price slide. It was off-market listings: 3,738,670 stones pulled from active listings in a single month, up 134% on February and a record high across the three months I've been tracking. New listings slowed at the same time, dropping 16% from February's unusually heavy intake. The market added a lot of stones in January and February, and now a meaningful chunk of them are gone. Whether that's sales, delistings, or retailers reshuffling their feeds, the velocity of turnover is worth paying attention to.

Active inventory still reached a record 27.6 million stones by month end, up 32% on February, and total inventory value crossed $90.3 billion. But the per-carat price tells a different story: the median fell to $972.73, down 18% from February and a new low for the tracking window. That's not a rounding error. Across the same three months, the median price per carat has dropped 34%, while the stones sitting in inventory have actually gotten larger, with the median active carat weight rising to 1.34ct (up from 1.21ct in both January and February). Bigger stones, cheaper per carat. The mix shift toward lab-grown explains most of it.

Lab-grown's share of active inventory hit 65.3% in March, up from 59.9% in February and the highest recorded so far. Lab-grown median price came in at $900.90, down nearly 9% on the month, with per-carat pricing at $561.86. Natural, by contrast, barely moved on price ($1,587.20 median, off just 1.2%) but saw its new listing volume collapse: 2.6 million new natural stones entered the market in March versus 4.9 million in February, a 47% drop. At the same time, natural off-market removals more than doubled. The natural segment is contracting in volume while holding its price. Lab-grown is expanding and softening. Both trends have been in motion for months.

Cross-retailer overlap climbed to 48.9%, another record, and the median spread across retailers carrying the same stone reached 92.8%, also a high. That spread figure is genuinely significant. When the same diamond lists at prices nearly double apart depending on where you find it, there's real money on the table for buyers who compare. A handful of names did most of the listing volume in March: the top five retailers accounted for 41.8% of all new listings. Concentration like that tends to widen spreads rather than narrow them.

Shape pricing moved in sharply different directions. Trillion cut had a brutal month, its median dropping from $1,230 to $659, down 46%. Asscher fell 21%, from $1,615 to $1,275. Pear slipped nearly 18% to $990. On the other side, the catch-all "other" category (which includes non-standard cuts and certain fancy shapes) rose 22% to a $2,193 median, and cushion edged up to $1,509. Round remained the dominant shape by volume at 42.6% of new listings, with a median of $915. Among the notable stones tracked this month, the most striking price contrast in lab-grown was a 70.83ct emerald cut IGI stone at $222,950 alongside a 55.23ct asscher at just over $21,000, a reminder that size alone doesn't set the price.

April's read will tell us whether that off-market spike was a one-month correction or the start of a sustained drawdown. If removals stay elevated while new listings remain subdued, active inventory could actually shrink for the first time in the tracking window. Natural volume is the other thread to watch: if new listings don't recover, natural's share of available stock will keep falling even if its prices hold. For buyers, the spread data alone makes the case for shopping across multiple retailers before committing. That 92.8% gap isn't noise.

Lucy Market Index

Ten numbers I record every snapshot.

Versus February 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.