The September Input-Cost Spike Has Unwound

What turned, and how fast

Between the second and fourth weeks of September 2026 the cost side of a poly-viscose quote went from the sharpest spike of the year to a broad retreat. Both halves of the blend turned, the petrochemical half and the cellulosic half, and so did cotton, which sets the tone for the spun-yarn market our blends compete with. This post is the counterpart to the ones published on the way up, and it is deliberately dated, because a cost direction is a snapshot and not a permanent fact.

The trigger was crude. Through the Hormuz escalation the official physical benchmark, the Europe Brent spot series published by the US Energy Information Administration, printed 121.25 dollars a barrel on 14 September and 130.80 on 15 September. The release of 23 September carries the series forward: 127.84 on 16 September, then 121.18, 119.66, 116.15 and 114.89 on 22 September, so the physical benchmark is down about twelve percent from its peak in a week. The US benchmark on the same release fell from 107.02 on 15 September to 96.41 on 22 September, below 100 from 21 September. On the futures measure the move ran further and faster: Brent futures fell for five consecutive sessions to 22 September on progress in renewed US-Iran talks and the restoration of operations at a key Saudi pipeline, then settled up about 3.9 percent at just over 103 dollars on 23 September after Iran's security council secretary said the strait would not reopen until Iran's conditions were met. Correction, 24 September: an earlier version of this paragraph described 23 September as a sixth losing session on the strength of intraday reporting. The session closed up, and the count was five.

Read those two paragraphs together carefully, because they are different instruments. A physical spot assessment and a futures contract are not the same number and a gap between them is not a contradiction. What is fair to say is that the escalation premium the market was pricing in mid-September has come out, and it came out in about a week.

The polyester chain followed within days

On the morning of 23 September the Chinese polyester complex, which is the price-setting market for the feedstocks behind Indian polyester, was lower across the board. Market reporting that morning carried PTA spot prices declining, the MEG dollar market trending lower, the MEG renminbi market lower on a weak note, PET bottle chip producers mostly lowering offers, and one major producer adjusting polyester DTY prices. Staple fiber and filament sales had been described as subdued, slack or bleak on each of the three preceding days.

The supply side was busy in the same window, with one PTA producer cutting its operating rate, another shutting a unit, a MEG unit shut in Taiwan, a PTA unit restarted and a new 1.5 million tonne per year unit launched. Shutdowns usually support a price. That they did not, in a week when crude fell, is the clearest evidence that demand rather than supply is now setting the direction.

This is a straight reversal of the frame this site published in August and held through mid-September, which was firm polyester with PTA and MEG lifted by costlier crude. That frame was right when it was written and it is not right today.

24 September 2026, and it cuts the other way. The complex bounced with crude's up session of 23 September: the renminbi MEG market was firmer on the morning of 24 September and October MEG futures on the Dalian exchange closed 3.4 percent higher that afternoon, while the large filament producers held their yarn offers unchanged and filament sales were still described as bleak. One up session in feedstock after five down sessions in crude is a bounce, by the same standard this post applies to crude itself. If it holds into the following week, that gets its own dated update rather than an edit here.

25 September 2026: the bounce widened. Brent futures settled up 3.4 percent at 106.60 dollars a barrel on 24 September, a second close above 100, and on the same afternoon the whole Chinese chain closed higher, not just MEG: January PTA futures up about 3.2 percent, November paraxylene up about 3.4 percent and November polyester staple fiber futures up about 3.0 percent, with the dollar MEG market rebounding and direct-spun staple fiber and filament sales both reported as improving. Two sessions is still short of a trend, and Brent was trading slightly lower on the morning of 25 September. What it does mean is that the lower input costs described above were a one-week window, and a quote priced on the bottom of that window should not be expected to hold. The next dated check on this post is the week of 28 September.

26 September 2026: the bounce did not carry through the week. Brent futures closed about 1.8 percent lower near 104.70 dollars a barrel on 25 September and WTI about 2 percent lower near 92.75, so crude is still above 100 on the Brent measure but has given back roughly half of the 24 September gain. One thing to know for the next fortnight: the Chinese fiber price service this post relies on is closed from 25 to 27 September and again from 1 to 7 October for the Mid-Autumn Festival and National Day holidays, resuming on 8 October, so there will be few fresh fiber price reads until then. A quote made in that gap is priced on the late-September level, not on new information.

1 October 2026: crude has now fallen back below 100. Brent futures closed near 98 dollars a barrel on 30 September, down roughly five percent on the session, and were trading a little over 96.5 early on 1 October, as markets were reported to be pricing in hopes of progress in US-Iran truce talks. That is a move on talks, not on a settlement, and the same talks have moved crude both ways in September, so we read it as the direction holding rather than as a new floor. Because the Chinese fiber price service is closed until 7 October, there is no polyester chain reading to set beside it yet.

2 October 2026: the move below 100 lasted one session. Brent futures rose about 4.4 percent to close at 102.31 dollars a barrel on 1 October, after a report that the US is sending a third aircraft carrier strike group to the Middle East, and were trading near 102.7 on 2 October. That is the same pattern as the rest of September, crude swinging both ways on talks and deployments rather than on any change in supply, so we still read the fiber leg as off its peak but not settled. A quote written this week should carry a short validity rather than lean on either the 30 September low or the 1 October rebound.

8 October 2026: the first polyester chain reading since the Chinese holiday, and it is firm. Paraxylene, the feedstock behind PTA, rose through the National Day break and closed at 1,283 dollars a tonne in Asia on 7 October, up about 2.7 percent on its level before the holiday, while MEG was reported stable and industrial polyester yarn was flagged for an upward price revision on 9 October. Brent futures were back near 101 dollars a barrel on 7 October. One firm week does not undo the September retreat, but it does mean the window for pricing on lower fiber inputs has not reopened, so the short-validity advice above stands. The physical oil price, as distinct from the futures price quoted here, is the reason, and it has turned back up: we cover it in why the physical barrel reads 120 when the news reads 100.

13 October 2026: crude has moved up again. Brent futures closed at 106.65 dollars a barrel on 12 October, on what markets were reported to see as renewed supply risk in the Middle East, and were trading near 104.8 on the morning of 13 October, about 1.7 percent lower. That is roughly five dollars above the 7 October level. It does not change the reading above, it strengthens it: the fiber side of a quote has not returned to its September lows, and a quote written now should still carry a short validity.

23 October 2026: crude has climbed again. Brent futures closed at 113.17 dollars a barrel on 22 October, up from about 108.8 two sessions earlier, and were trading near 114.4 on the morning of 23 October, with markets citing renewed Middle East tension. Reported closing figures for 22 October differ by about a dollar between data providers, so treat the level as approximate. Freight on the Shanghai lanes rose in the same week (see below), while Indian polyester-viscose and cotton yarn were still reported soft on weak demand, though raw cotton itself rose sharply in the same ten days on thin new-season arrivals (our October cotton post). So the dollar-priced inputs are rising again while yarn has not followed yet; a quote written now should carry a short validity rather than assume the late September easing continues.

Cotton and cotton yarn turned too, for their own reasons

ICE cotton for December delivery settled near 82.9 US cents per pound on 23 September after a sharp rally on 22 September and a smaller give-back the next day, so on the week it is flat to slightly higher rather than easing further. On the month it is down about six to seven percent, depending on the reference day. Year on year it is still up about thirty percent, which is the figure worth holding on to: this is a retreat from a high, not a return to a cheap market. Earlier in September this site published a year-on-year figure of roughly thirty-four percent, and that number is now stale.

The driver is the harvest. As the US seasonal harvest progresses, new-crop supply arrives against demand that reporting describes as not keeping pace. The Chinese futures market moved the same way, closing lower on 22 September and opening lower again on 23 September, which broke the single up session recorded on 21 September.

On the yarn side, reporting of 22 September has South Indian cotton yarn prices falling in Mumbai and Tiruppur on weak demand, tight payment cycles, volatile futures and limited export orders, with the Cotton Corporation of India cutting its selling prices. That matters to this site specifically, because it reverses the surge framing of a post published earlier this month.

Viscose is the exception that proves the point. A staple fiber quotation was raised in mid-September, and there has been no follow-through: as of 23 September the cellulosic market reads steady rather than firming, with refined cotton sentiment holding, lyocell prices unchanged and rayon yarn changing little.

Freight has barely moved, and that is the useful part

One leg of the cost stack has not joined the retreat. The weekly container assessment for Thursday 17 September had the composite index up one percent to 4,500 dollars per forty-foot container, and the next one, for 24 September, had it down one percent to 4,468 dollars, so over two weeks the composite has gone sideways rather than down. The fall came entirely from Asia-Europe, where Suez Canal transits rose from 41 in week 37 to 48 in week 38 and added effective capacity, while Shanghai to Los Angeles rose another two percent on blank sailings. The assessor expects rates to ease again ahead of China's Golden Week holiday in early October.

So a buyer who reads that oil has collapsed and concludes that the whole delivered cost of cloth is falling has drawn the conclusion too wide. Fiber inputs have turned. Ocean freight, for now, has not, and the Gulf leg in particular is unaffected by the Suez recovery that is pulling Asia-Europe rates down.

1 October 2026: the composite fell another one percent to 4,434 dollars per forty-foot container, so it is still moving sideways. Asia-Europe is now the clear exception: Shanghai to Genoa fell three percent and Shanghai to Rotterdam two percent on the week, and the assessor records Asia-Europe rates as having declined for twelve consecutive weeks on weak demand and rising Suez transits. Carriers are trying to push rates back up with higher spot tariffs for the second half of October, and the assessor expects rates to ease again over the Golden Week holiday. For a buyer in Europe that is a real easing in the freight leg; for a buyer in the Gulf or the United States it is not, and Shanghai to New York actually rose one percent.

8 October 2026: the composite fell two percent to 4,351 dollars per forty-foot container, and for the first time in this series the fall was not Asia-Europe alone. Shanghai to Los Angeles fell three percent and Shanghai to New York two percent as demand softened over China's Golden Week, while Shanghai to Rotterdam fell another two percent and Shanghai to Genoa held flat. The assessor records Asia-Europe rates down for thirteen consecutive weeks and calls the faster than expected return to the Suez route the biggest threat to carrier efforts to hold rates. That is a broader easing than a week ago, but it is a holiday-week reading on two lanes that rose through September, so a buyer in the United States should treat it as one soft week rather than a turn. Nothing in the index speaks to the Gulf leg.

15 October 2026: the composite rose three percent to 4,485 dollars per forty-foot container, and the lane behind it is the one that had been falling. Shanghai to Rotterdam rose six percent and Shanghai to Genoa seven percent, the first Asia-Europe rise after thirteen consecutive weekly declines, as cargo flows resumed after Golden Week. The assessor does not read it as a turn: fewer blank sailings and resumed Suez transits are adding capacity on the route, carriers are trying to push higher spot tariffs from 19 October with uncertain success, and it expects rates to stay stable next week. Shanghai to Los Angeles rose three percent and Shanghai to New York fell one percent. One rising week after thirteen falling ones is a pause, not a reversal, so a buyer in Europe should not yet assume freight is climbing again, and should not assume it will keep falling either.

22 October 2026: the composite rose two percent to 4,585 dollars per forty-foot container, the second weekly rise and the highest reading in fifteen weeks. Shanghai to Rotterdam rose three percent and Shanghai to Genoa five percent, and the assessor counts eight blank sailings on Asia-Europe for the following week against two the week before, which it reads as carriers cutting capacity to push rates up. Shanghai to Los Angeles rose two percent and Shanghai to New York one percent. Two rising weeks after thirteen falling ones ends the easing we described on this lane, so a buyer in Europe should no longer assume freight is coming down, though one more week is needed before calling it a climb.

What this does to a quote, and what it does not

The honest answer is: less than you would like, and later than you would like. Cost pressure travels one way down this chain, from crude toward cloth, and it arrives with a lag at every step, because each stage works through inventory bought at the old price before it buys at the new one. That lag is symmetric. It slowed the increase down on the way up and it will slow the decrease down on the way back.

In practice that means a barrel priced on 23 September is a fiber price in October and a yarn price after that, and greige bought weeks ago is still greige bought weeks ago. A mill quoting today is quoting against yarn it has already contracted for.

The second thing it does not do is reverse anything on the policy side. None of the moves described here touch a duty rate, an origin rule or a scheme deadline. A buyer landing cloth in a market with a tariff on it is still paying that tariff, and for most of our export destinations the duty at the buyer's own border is a larger number than a month of fiber movement.

The reasonable thing to do with a falling input market is not to reopen a live order. It is to time the next one. If your reorder window is flexible, the case for placing in late October rather than late September is now better than it was, provided freight does not take back what fiber has given.

Where this leaves the posts published on the way up

This site published three posts during the September run-up whose central claims have now reversed or aged: one on polyester and poly-viscose prices rising, one on cotton prices being high again, and one on a cotton yarn price surge. Each of those now carries a dated line pointing here. They are not being quietly rewritten, because a dated snapshot that was accurate when published is a record rather than an error, and a buyer who read one in September should be able to see what changed.

This post will be treated the same way. If the retreat reverses, that gets its own dated update rather than an edit here.

26 October 2026: the retreat has reversed. Brent futures closed at 116.72 dollars a barrel on 23 October, above their mid-September level, so the headline of this post no longer describes the market. The October climb and what it means for a quote are in Crude Is Back Above 110.