Morning Market Briefing for the C5 Industry Chain

I. Key Focus Points

1. Crude Oil Prices Decline: Expectations of improved repair progress on Saudi Arabian oil pipelines, combined with signs of easing tensions in the Middle East, led to a drop in international crude oil prices. The NYMEX WTI futures contract for October delivery closed at $100.3/barrel, down $1.61/barrel (-1.58% WoW). The ICE Brent futures contract for November delivery closed at $103.87/barrel, down $0.95/barrel (-0.91% WoW). China's INE crude oil futures contract (November 2026 expiry) fell by 50.6 yuan to 754.4 yuan/barrel; the night session dropped a further 19.6 yuan to 734.8 yuan/barrel.
2. Naphtha Prices Drop: As of September 18, Japanese naphtha closed at $902.25/ton, down $18.5/ton from the previous trading day. Singapore naphtha closed at $97.26/barrel, down $2.4/barrel from the previous trading day.
3. Domestic Pyrolysis C5 Market: Yesterday, prices from major domestic pyrolysis C5 producers remained stable. However, private enterprises continued to significantly cut their pyrolysis C5 prices today, with some dropping to 7,100 yuan/ton. Shandong mixed C5 prices declined intraday, and sales-to-production ratios remained sluggish. Weak shipments of residual liquid had a notable negative impact on pyrolysis C5. In terms of deep processing, piperylene monomer prices were acceptable, and petroleum resin quotes remained firm. However, downstream purchasing enthusiasm was moderate, driven primarily by rigid demand.
4. Pyrolysis C5 Residual Liquid: Yesterday, some suppliers in the domestic pyrolysis C5 residual liquid market held prices steady while waiting for market clarity, though sporadic declines occurred. Gasoline prices in the Shandong market fell. Prices for homogeneous products like mixed C5 also dropped. The market sentiment was predominantly bearish, leading some residual liquid suppliers to maintain stable prices while others lowered them.
5. Piperylene Market: Yesterday, the domestic piperylene market was largely stable, with localized price increases. Overall factory inventories remained low. However, recent weakening in private-sector pyrolysis C5 feedstock prices has made traders cautious, with negotiations focused on rigid demand. Mainstream ex-factory prices ranged from 8,900 to 10,000 yuan/ton.
6. Isoprene Market: Yesterday, domestic isoprene prices consolidated at high levels. Downstream SIS (Styrene-Isoprene-Styrene block copolymer) faced significant resistance to price hikes, limiting its ability to accept higher raw material costs. Market participants are closely monitoring upcoming changes in SIS plant operations. Mainstream bid/ask prices in the East China market ranged from 13,600 to 14,200 yuan/ton.
7. Dicyclopentadiene (DCPD): Yesterday, DCPD maintained a stable trend within the range of 8,900–9,300 yuan/ton. Low-end prices were stable, while high-end spot prices involved negotiation. With the approaching short holiday, end-user orders were limited, and pre-holiday stocking sentiment was mediocre. Currently, private-sector feedstock prices have fallen sharply, but cost support remains relatively solid due to stable prices from major producers. Overall DCPD supply is not abundant, providing continued support for maintaining high-level trends.
8. Road Marking Paint C5 Petroleum Resin: Yesterday, mainstream prices for road marking paint C5 petroleum resin rose by 0–200 yuan to 9,600–11,000 yuan/ton. High-grade resin remains in short supply, pushing prices up. However, downstream acceptance of high prices is weakening, and market trading activity has cooled. Mainstream transaction prices remained stable.
9. Adhesive C5 Petroleum Resin: Yesterday, mainstream prices for piperylene-based adhesive C5 petroleum resin were 11,500–13,600 yuan/ton, while de-cyclohexane-based adhesive C5 petroleum resin ranged from 10,800–11,200 yuan/ton. Spot availability remains tight, with almost no stock available for September. Some manufacturers have suspended quotes ("closed board"). Negotiation centers continue to shift upward within the current ranges.

Core Logic: Pyrolysis C5 consolidating; Isoprene stable; Piperylene seeing localized gains; DCPD temporarily stable; C5 petroleum resins showing small upward pushes amidst stability.

II. Price Summary Table

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

III. Market Outlook

• Pyrolysis C5: Domestic pyrolysis C5 prices are expected to remain temporarily stable. Shandong mixed C5 prices are projected to continue declining. Private enterprises are likely to reduce inventory before the holiday, exerting downward pressure on prices. Poor recent shipments of residual liquid have weakened some enterprises' willingness to purchase feedstock. Regarding deep processing, piperylene monomer inventories are low, providing some support, while resin end-users are primarily buying based on rigid demand.
• Pyrolysis C5 Residual Liquid: The market is expected to weaken and decline. Gasoline refineries have been accumulating inventory for several consecutive days, suggesting mixed C5 prices may fall further. Market sentiment is bearish. Chempricehub predicts that refinery prices for pyrolysis C5 residual liquid will mainly trend downward in the near term.
• Mixed C5: Crude oil markets experienced minor fluctuations during the session, having limited impact on the broader market. Yesterday, refinery gasoline prices dropped, improving shipment sentiment. Mixed C5 prices declined, increasing downstream willingness to buy. Chempricehub expects mainstream mixed C5 prices to stabilize today, with sporadic catch-up declines.
• Isoprene: Prices are expected to consolidate at high levels. The tight supply pattern continues, and factories' determination to hold prices provides support. However, crude oil volatility and weakening private-sector pyrolysis C5 prices have made traders cautious. Prices are expected to remain in a high-level consolidation phase as participants wait and see.
• Piperylene: Prices are expected to remain temporarily stable. While the decline in private-sector pyrolysis C5 feedstock prices has slightly reduced cost support, the product's own supply remains tight. Additionally, rising resin prices have attracted market attention. Piperylene prices are expected to consolidate temporarily. (Note: The source text repeats this outlook twice with slight variations; the essence is temporary stability due to tight supply vs. weak feedstock cost support).
• Dicyclopentadiene (DCPD): Prices are expected to remain elevated. Although downstream demand is average, spot supplies are tight and unlikely to ease in the short term. Coupled with the pre-holiday stocking cycle for the Mid-Autumn and National Day festivals, supply and cost factors will dominate the market in the short term, supporting a firm, high-price trend.
• C5 Petroleum Resins: For road marking paint resin, end-user construction volumes may be delayed due to high raw material costs, and downstream price acceptance is weak. With a slight increase in resin supply, prices are expected to remain firmly high in the short term, with limited room for further upside. For adhesive resin, prices have seen a clear push upward recently. Due to supply gaps during the peak season, prices are expected to continue small incremental rises.

IV. Data Calendar

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