C5 Industry Chain Market Morning Briefing (September 11, 2026)

I. Key Points

1. There are no signs of easing in the U.S.-Iran conflict. The Houthis continue to pressure Saudi Arabia, supply risks keep increasing, and international oil prices continue to rise. NYMEX crude oil futures October contract stood at 102.48, up 6.43 USD/bbl, or +6.69% from the previous day; ICE Brent crude oil futures November contract stood at 107.63, up 6.42 USD/bbl, or +6.34% from the previous day. China INE crude oil futures 2610 contract rose 45.9 to 768.4 yuan/bbl, and in night trading rose 47.6 to 816 yuan/bbl.

2. As of the 10th, Japanese naphtha closed at USD 908.5/t, up USD 4.75/t from the previous trading day. Singapore naphtha closed at USD 96.62/bbl, up USD 0.44/bbl from the previous trading day.

3. Yesterday, prices from major domestic cracked C5 producers were stable, Shandong mixed C5 prices were temporarily stable, and the production-sales rate was acceptable. Rising crude oil prices provided some support to the market. The oil products sector is facing stricter standards, and residual liquid in some regions has been affected, with participants remaining on the sidelines. In deep processing, diene monomer prices were firm, and resins were supported by costs, but end-user purchasing enthusiasm remained weak.

4. Yesterday, the cracked C5 residue market was mostly stable, with scattered refineries posting catch-up increases. The gasoline market in Shandong rose overall, while downstream purchasing sentiment weakened. The homogeneous product mixed C5 was stable and range-bound, with Shandong quotation at 7,880 yuan/t. As market compliance became stricter, the cracked C5 residue market held stable amid a wait-and-see mood, with scattered plants posting catch-up increases.

5. Yesterday, domestic piperylene was stable and consolidating. Crude oil disturbed broad commodity fluctuations, market participants operated cautiously, and trading was mainly small-lot rigid demand. Mainstream ex-works prices were 8,500-9,300 yuan/t.

6. Yesterday, domestic isoprene was mainly stable, with slight increases in some areas. In-market trading continued to be based on rigid demand, and participants cautiously watched the outlook. Mainstream offer/bid prices in the East China market were 13,200-13,800 yuan/t.

7. Yesterday, dicyclopentadiene remained temporarily stable, in the range of 8,300-8,900 yuan/t. The low end was for stable customers, while spot goods tended toward the high end, and some small-lot auctions climbed above 9,000 yuan/t. Currently, spot supply remains tight, and feedstock continues to rise. In the short term, supply is unlikely to ease, and the high-price trend continues.

8. Yesterday, mainstream prices of C5 petroleum resin for road marking paint were 9,300-10,300 yuan/t. International oil prices continued to rise; domestic C5 resources were tight and prices were still expected to rise; price inversion occurred for some resins, and demand in the north continued to edge up, so negotiated prices continued to be pushed higher.

9. Yesterday, mainstream prices of piperylene-based adhesive C5 petroleum resin were 10,500-12,500 yuan/t, while mainstream prices of decyclized adhesive C5 petroleum resin were 10,000-10,800 yuan/t. Spot volumes remained tight and costs continued to rise. Downstream risk-aversion was also strong, with buying mostly limited to rigid demand. In the short term, shortage dominates, and negotiated prices continue to rise steadily.

Core logic: cracked C5 up, isoprene slightly up, piperylene stable, dicyclopentadiene temporarily stable, and C5 petroleum resin steady with a slight upward push.

II. Price Table

Table 1 Domestic Cracked C5 Industry Chain Summary (Unit: yuan/t)

III. Market Outlook

Domestic cracked C5 prices are expected to remain firm. Crude oil closed sharply higher, Shandong mixed C5 prices are at a high level, and there is still a price spread compared with cracked C5. Private enterprise auction prices are firm, but oil product market regulation is increasing, so the impact on light components should be watched cautiously. In terms of diene monomers, low diene monomer inventories are supporting continued price increases. Resin shipments are moderate, but cost support is strong, and resins are rising under cost support.

The cracked C5 residue market is expected to fluctuate with an upward bias. Overnight crude oil rose sharply, gasoline refineries continued to push up prices, and their ability to hold prices is relatively strong. With port order inventories, the mixed C5 market has support at the bottom. However, recent market operating standards have become stricter. Considering all factors, Chempricehub Information expects cracked C5 residue refineries to fluctuate with a stronger bias today.

Overnight crude oil rose significantly. Boosted by crude oil, gasoline refineries continued to raise prices substantially. With dual positive factors from crude oil and gasoline, and with refinery mixed C5 spot supply tight, Chempricehub Information expects the mixed C5 market to be mainly firmer today.

Isoprene is expected to run firm. The tight supply pattern continues, and the cost side is strengthening, supporting factories' reluctance to sell at low prices. Prices are expected to consolidate with an upward bias.

Piperylene is expected to consolidate with an upward bias. Recently, the cost side has strengthened, combined with lower plant output and support from higher self-use inventories, and tradable market resources are limited. Piperylene is expected to continue to run firm.

Dicyclopentadiene prices are expected to remain at relatively high levels. Although downstream demand is moderate, spot supply is tight and unlikely to ease in the short term, and feedstock prices provide clear cost support. In the short term, supply and cost factors dominate the market, and prices are expected to remain firm at highs.

For C5 petroleum resin used in road marking paint, downstream construction activity is relatively concentrated in the north, and raw material C5 prices have risen notably, so negotiated prices continue to edge up. For adhesive C5 petroleum resin, producers' cost pressure is rising, and downstream rigid demand is stable with a slight increase. Given cost pressure, prices continue to rise slightly.

IV. Data Calendar

Table 2 Domestic Cracked C5 Industry Chain Data Overview (Unit: 10,000 t)