Benchmark polished diamonds prices moved 7.3% over the past four weeks, the sharpest swing since Q2 FY27, as inventories abroad normalised and shipping schedules recovered. The move has quickly filtered into spot quotes at Nhava Sheva, where dealers reported narrower spreads and thinner volumes through the week.

Credit conditions have helped. Working-capital spreads for Earth Sciences borrowers narrowed by roughly 25 basis points, and corporate bond issuance from the sector reached $8.3 billion for the year to date, the highest in three years. Rating agencies have upgraded four issuers while downgrading none.

What moved and why

Equity markets have taken a constructive view of the sector. The Earth Sciences index gained 7.3% over the quarter, outpacing the broader market by about two percentage points, with the largest moves in names that disclosed order books extending beyond twelve months.

Physical premiums tell a similar story. Delivered premiums at Nhava Sheva compressed by about $382 million per tonne equivalent, and buyers report that sellers are now willing to quote longer validity periods, a reversal from the short-fuse offers that dominated earlier in the year.

On the other side of the ledger, producers are watching margins. Realisations for domestic Earth Sciences suppliers fell 8.1% on the month, and two listed companies trimmed guidance in post-results calls. Management teams pointed to input cost relief as a partial offset, but warned that price competition would intensify.

“Chasing a falling price is how treasurers get hurt. Layer in, do not lunge.”

Winners, losers and margins

Derivatives data points to cautious positioning. Open interest in polished diamonds contracts rose 30.8% while implied volatility eased, a pattern desk traders read as hedgers adding protection rather than speculators adding risk. Options skew suggests more demand for downside protection than for upside.

For corporate buyers, the practical advice from risk consultants is to layer hedges rather than chase the move: cover 40 to 60 percent of the next two quarters at current levels, keep optionality for the remainder and revisit after the next inventory report.

Positioning and hedging

Strategists are less unanimous about what comes next. One brokerage raised its target for the sector on earnings upgrades, while another cut its rating citing valuations at 8.1% above the five-year average. The disagreement, one fund manager noted, is itself a sign that the trade is maturing.

Currency is an important second driver. The rupee traded in a narrow band against the dollar, helped by steady inflows and a decline in crude, and forward premiums eased to levels that make hedging more attractive for importers with a three-to-six month horizon. Treasury heads say they are extending hedge tenors.

The range ahead

The immediate beneficiaries are importers who left positions unhedged. Asian Paints, which buys roughly 2,359 tonnes a quarter, said it had trimmed its landed cost by 30.8% since the start of the month and was deferring forward purchases in anticipation of further softness.