Morning Market Brief for the C5 Industry Chain (September 17, 2026)

I. Key Focus Points

1. Efforts by multiple parties to ease tensions in the Middle East, combined with the Federal Reserve's interest rate hikes boosting the US dollar exchange rate, led to a decline in international crude oil prices. NYMEX WTI crude oil futures (October contract) closed at $102.43/barrel, down $3.40/barrel (-3.21% WoW); ICE Brent crude oil futures (November contract) closed at $105.83/barrel, down $2.92/barrel (-2.69% WoW). China INE crude oil futures (contract 2611) rose by 2.2 yuan to 838.4 yuan/barrel during the day session but fell by 33.6 yuan to 804.8 yuan/barrel during the night session.

2. As of the 16th, Japanese naphtha closed at $941.25/ton, down $15.12/ton from the previous trading day. Singapore naphtha closed at $102.39/barrel, down $0.08/barrel from the previous trading day.

3. Yesterday, domestic prices for cracked C5 from major state-owned enterprises remained stable. Prices for Shandong mixed C5 declined significantly. Private enterprise auctions were lackluster, leading to some inventory accumulation. High prices pose certain market risks. Regarding deep processing, isoprene and piperylene monomer prices remained firm. Resin prices are supported by costs, but end-user purchasing enthusiasm remains weak.

4. The domestic cracked C5 raffinate market maintained stability yesterday, executing existing contracts, though minor declines occurred in some segments. Supported by crude oil trends, gasoline prices in the Shandong market rose, but downstream receiving sentiment was poor. Supply-demand advantages for the substitute product, mixed C5, have ended, leading to price declines. The cracked C5 raffinate market held steady while awaiting further developments, with slight declines in isolated markets.

5. Domestic piperylene prices rose partially yesterday. Overall factory inventories remain low, and pending delivery orders support a strong pricing stance. Downstream users passively followed the price increases, resulting in significant resistance to transactions. Mainstream ex-factory prices ranged from 8,900 to 10,000 yuan/ton.

6. The domestic isoprene market continued its firm trend yesterday. Tight supply continues to provide support, and factories are reluctant to sell at lower prices. However, feedstock cracked C5 weakened recently among private enterprises, causing buyers to remain cautious. Mainstream bid/ask prices in the East China market ranged from 13,600 to 14,200 yuan/ton.

7. Dicyclopentadiene (DCPD) maintained a firm trend yesterday, with prices ranging between 8,600 and 9,200 yuan/ton. Low-end prices remained stable for regular customers, while high-end spot prices were subject to negotiation. Some auction prices were slightly higher. Spot supply remains tight, and inventories are generally low. Combined with cost support from raw materials, the high-price trend is expected to continue in the short term.

8. Mainstream prices for road marking paint C5 petroleum resin ranged from 9,600 to 10,600 yuan/ton yesterday. Tight domestic C5 resources caused operating rates at some plants to decline further. Localized negative margins appeared for resin producers, while overall demand continued to rise slightly. Negotiated prices were pushed up further, although downstream acceptance of high-end prices weakened.

9. Mainstream prices for piperylene adhesive C5 petroleum resin ranged from 11,000 to 13,000 yuan/ton, while hydrogenated adhesive C5 petroleum resin ranged from 10,600 to 11,000 yuan/ton. Spot availability remained tight, and costs continued to rise. Short-term shortages dominated downstream procurement, pushing negotiated prices higher.

Core Logic: Cracked C5 consolidated; Isoprene edged up; Piperylene rose; Dicyclopentadiene rose; C5 petroleum resins remained stable with slight upward pressure.

II. Price List

Table 1: Summary of Domestic Cracked C5 Industry Chain (Unit: Yuan/Ton)

III. Market Outlook

Domestic cracked C5 prices are expected to remain temporarily stable. Shandong mixed C5 prices are likely to retreat. Auctions by private enterprises are expected to be average. Potential risks arising from changes in the light fraction market should be monitored. However, mixed C5 still maintains a price spread advantage over cracked C5, providing some support. Regarding pentadiene monomers, inventories are low and prices are firm. Resin sales are moderate but supported by costs.

The cracked C5 raffinate market is expected to weaken and decline. Refinery gasoline inventories are low, providing some confidence to hold prices. Supply-demand advantages for the mixed C5 market have diminished, leading to a slight decline in prices. Considering all factors, Chempricehub Information predicts that refinery prices for cracked C5 raffinate will decline slightly today.

Overnight crude oil prices rose. Large-volume trades at ports performed well yesterday. With refinery gasoline inventories remaining low, sellers may hold prices and ship goods today. Mixed C5 shipments were acceptable yesterday. Chempricehub Information predicts that the mixed C5 market will consolidate within a narrow range today.

Isoprene is expected to consolidate at high levels. Although crude oil closed lower, the tight supply pattern for isoprene continues, supporting factories' reluctance to lower prices. Prices are predicted to remain firm at elevated levels.

Piperylene is expected to remain temporarily stable as the market waits for direction. Despite the drop in crude oil closing prices, reduced factory output and increased internal consumption provide support. Limited tradeable resources are available in the market. Piperylene prices are expected to stabilize and consolidate.

Dicyclopentadiene is expected to continue running at relatively high levels. Downstream demand performance is average, but spot supplies remain tight with no immediate relief expected. Strong cost support from raw material prices, combined with pre-holiday stockpiling ahead of the Mid-Autumn Festival and National Day holidays, means that supply and cost factors will dominate the market in the short term. Prices are expected to maintain a firm trend at high levels.

For road marking paint C5 petroleum resin, downstream construction activity is concentrated in northern regions. In the short term, resin costs will remain high, and operating rates will stay low, leading to continued slight price increases. For adhesive C5 petroleum resin, rising producer costs and increasing rigid downstream demand will also drive continued slight price increases.

IV. Data Calendar

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