Princess Cuts Rallied 7% as Lab-Grown Supply Flooded the Market

Princess cuts gained $71 per carat in a single week. Ovals dropped $23. Lab-grown supply surged 66%, dumping over 1.2 million new listings onto the market. The week ending April 13 produced the sharpest shape rotation we've tracked this year, wrapped inside a broader market that kept splitting along the natural versus lab-grown fault line.

Two markets pulling further apart

Natural and lab-grown diamonds moved in opposite directions last week, and both moves carried weight.

Natural diamond prices eased 1.77% on average, settling at $1,503. Not a crash. More like the slow, steady softening that's been characterising the natural market for months. The more telling signal came from the supply side: natural listings contracted 14.5%, with nearly 298,000 stones pulled off the market while only 571,000 remained active. Retailers weren't just watching the natural market cool. They were actively trimming inventory, whether through seasonal adjustment or deliberate pruning of slow sellers.

Lab-grown told a completely different story. Average prices climbed 18.4%, landing at $856, but context matters here. That uplift arrived alongside a 66% supply surge, meaning the new inventory flooding in carried higher average specifications (and therefore higher prices) than what was already listed. Individual lab-grown stones weren't necessarily getting more expensive. The mix changed. When a wave of premium inventory enters the market all at once, the average lifts even if no single stone costs more than it did the week before.

Metric	Natural	Lab-Grown
Active Listings	571,138	1,842,891
Average Price	$1,503	$856
7 Day Price Change	-1.77%	+18.4%
Supply Change (7d)	-14.51%	+65.94%
Price Gap		43% below natural

The 43% price gap between natural and lab-grown held roughly steady. For a buyer weighing a 1.5ct G VS2 round, that gap translated to somewhere between $600 and $900 in real dollars depending on where they shopped. Nothing in last week's data suggested this spread was about to narrow.

Step cuts had a proper moment

Princess, emerald, and asscher cuts all posted strong gains during the week, and the moves were large enough across enough inventory to mean something.

Princess cuts led with a $71 per carat gain on a $1,000 per carat median. A 7.1% weekly move across 78,000 active listings is genuinely significant for a shape category this deep. Emerald cuts climbed $46 per carat on a $1,219 base (3.8%), while asscher cuts added $19 per carat on a higher $1,402 median (1.4%).

Shape	Listings	Median $/ct	7d Move	% Change
Princess	78,351	$1,000	+$71	+7.1%
Emerald	186,338	$1,219	+$46	+3.8%
Asscher	32,102	$1,402	+$19	+1.4%
Oval	446,099	$900	-$23	-2.6%
Trillion	1,005	$776	-$21	-2.7%

The rally fits a pattern that's been building for weeks. As round and oval prices compress under lab-grown pressure, buyers looking for something distinctive have been rotating into step cuts. Princess cuts sit at an interesting intersection: they deliver the brilliance that round buyers want, but with a geometric silhouette that feels more deliberate. At $1,000 per carat they're also meaningfully cheaper than asschers, which may explain why they attracted the biggest move.

Whether this was a sustained rotation or a single week pop wasn't clear yet. But the princess number was real, spread across enough inventory that it wasn't a handful of premium listings dragging the median upward.

Ovals kept sliding

If step cuts were the week's winners, ovals were the clearest losers. Again.

Those 446,000 oval listings (more than any other fancy shape by a factor of two) saw their median per carat price drop $23, settling at $900. A 2.6% weekly decline might not sound dramatic in isolation, but ovals had been softening for weeks, and the compounding effect was starting to show. A stone that cost $925 per carat three weeks ago was now going for $900. Over a 2ct diamond, that's a real $50 savings for anyone patient enough to have waited.

The mechanism was straightforward. Lab-grown supply surged hardest in the shapes that sell best, and ovals sell best. When manufacturers produce oval lab-grown stones efficiently and retailers list them aggressively, the floor drops. Natural ovals get pulled down too, because buyers increasingly compare across both origins before committing.

For buyers, the softness was actually welcome. A 2ct oval in the G to H colour range with VS2 clarity was easier to find under $2,000 last week than at any point we tracked in the prior quarter.

Trillions also fell 2.7%, but with only 1,005 listings in the entire market, that's too thin a pool to draw conclusions from.

A supply flood with real consequences

Total active inventory across the platform hit 27.1 million listings last week, up 6% from the prior period and extending a seven period upward trend that had added 28.4% to total supply. New listings jumped 35.7%, reaching 2.4 million additions. Delistings, meanwhile, collapsed: stones going off market fell 77.6%, plummeting from 3.9 million in the prior period to just 872,000.

That combination tells a very specific story. Retailers flooded inventory onto the market and pulled far fewer stones back. In the natural segment, the 14.5% supply contraction pointed toward curation: fewer stones, presumably better selected, with dead weight cleared off the shelves. In lab-grown, the 66% supply explosion was the dominant force. Manufacturers across India and China continue to scale CVD and HPHT production capacity. What actually reaches retail is a fraction of total output, and that fraction grew sharply.

For buyers, more supply is unambiguously good news. More competition between retailers. More stones to compare. More pricing pressure on individual listings. And the rising cross-retailer overlap (47.6% and climbing for seven consecutive periods) meant nearly half of all certified diamonds appeared at multiple retailers, giving buyers genuine leverage to shop the same stone across different sellers and take the lowest price.

The cross-retailer spread was still enormous

The median price spread between the cheapest and most expensive listing of the same certified diamond sat at 89.8% last week. Not the worst case. Not the tail of the distribution. The median. Half of all shared diamonds carried an even larger gap.

In practical terms: a lab-grown 1ct round with F colour and VS1 clarity might have been $780 at one retailer and $1,480 at another. Same stone. Same certificate number. Same lab report. The only difference was margin.

Cross-Retailer Metric	Value
Overlap (same stone, multiple retailers)	47.6%
Median Price Spread	89.8%
Trend	Rising for 7 consecutive periods

With nearly half the market's diamonds listed at more than one retailer, comparing prices on the same certified stone was the single most impactful thing a buyer could do. Every other consideration, shape preference, colour grade, setting style, mattered less than whether you were paying $780 or $1,480 for an identical diamond. The overlap kept growing, too, up 7.9% over the trailing seven periods as more retailers tapped into shared supplier networks like Nivoda and VDB. Good for buyers who knew where to look. Expensive for those who didn't.

What we were watching next

The princess cut rally was the week's most obvious open question heading into April 14. A 7.1% gain either signals a genuine shape rotation or snaps back equally fast. A second consecutive week of gains would make the trend look structural rather than noisy, and princess buyers who moved quickly during the rally would have caught a genuinely good window.

Equally important was the lab-grown supply trajectory. Adding 1.2 million listings in a week isn't sustainable at that rate, but production capacity showed no sign of plateauing. Whether prices held or softened alongside the supply flood would determine if the lab-grown market was entering a new phase of price discovery where manufacturing cost, not retail positioning, sets the floor.

On the natural side, a 14.5% weekly supply contraction deserved monitoring. If retailers kept tightening inventory, buyers shopping in the $3,000 to $8,000 range would start seeing fewer options and firmer prices. If it reversed, the contraction was seasonal housekeeping rather than a strategic shift.

For anyone who was shopping during this window, the calculus was straightforward: step cuts were running hot but still reasonably priced below 2ct, ovals were soft and getting softer, and whatever price you found first was almost certainly not the best one available for that stone.