When Brent crude plunged 7.3% to $81.55 per barrel on the morning of August 3, the domestic polyester filament market remained almost unmoved. This contrast is not accidental but the inevitable result of inventory restructuring over the past few months. The wild swings in crude oil are losing their command over polyester filament prices; the real driver is the inventory level change brought by sustained production cuts in the weaving sector.
Event Background: Oil's Rollercoaster vs. Filament's Calm
The immediate trigger for this round of oil volatility was the Trump administration's policy reversal toward Iran between July 31 and August 2. From threatening to strike energy facilities to announcing imminent talks, the stance shifted within three days. Brent's October contract recorded a single-day drop of 7.3%, and WTI fell below $80 per barrel. Such policy-driven moves sparked sharp reactions in the financial markets, but the transmission to the industrial chain was clearly muted.
Notably, this is another round of US-Iran conflict this year. Since the first clash in late February, every Trump statement has caused short-term oil fluctuations, yet polyester filament prices have maintained a small daily change of 50-100 yuan, sometimes even remaining flat when oil plunges. This divergence indicates a fundamental shift in the pricing logic of the filament market.
Industry Impact: Inventory Restructuring Reshapes Pricing Power
The core reason for filament's independent trend lies in the downstream weaving sector's shift from speculative stockpiling to rigid replenishment. Currently in the traditional off-season, weaving machine operating rates are below 50%, and many enterprises lacking stable orders have cut or halted production. In this context, raw material purchases are kept at minimum inventory turnover, and small price fluctuations have little impact on rigid-demand customers.
More critically, the sustained production cuts over the past half-year are altering the supply-demand balance of greige fabric. Industry public data shows that the average fabric inventory in mills has dropped by more than 10 days compared to the same period last year. The significance is that when demand recovers in late August, existing inventories may not support the first wave of procurement. Moreover, fabric prices often rise before inventories are fully depleted; once signs of tightening emerge, sellers tend to hold back, pushing prices up.
This implies that pricing power is shifting from upstream oil to midstream inventory. Over the past two years, weaving enterprises lacked bargaining power due to high inventories; now with lower inventory levels, the buyer's market pattern may loosen. For filament plants, this means that the transmission of raw material cost fluctuations to quotations weakens, while the order elasticity from downstream demand recovery becomes a more important price driver.
Time Variable: Late August May Be a Turning Point
In the short term, the crude oil market is likely to remain volatile, with Trump's policy uncertainty dominating sentiment, while polyester filament prices are expected to continue small fluctuations. But time is the biggest variable—the traditional off-season is expected to last another half month, during which demand is unlikely to improve significantly.
However, two factors are accumulating momentum for a turn. First, the blockade of the Strait of Hormuz and the Bab el-Mandeb has substantially hindered oil transport; even if some tankers pass, transportation costs have risen sharply, which will exacerbate oil supply shortages in some countries in the coming weeks, pushing up the energy price center. Second, the seasonal window for downstream demand recovery is approaching. Once orders pick up, the low fabric inventory may trigger a chain reaction: first, some mills hold back sales, then quotations rise, and then filament procurement expands.
For market participants, late August deserves close attention. If demand recovers as expected, filament prices may break out of the current narrow range and enter a replenishment-driven uptrend. However, caution is needed: if oil prices fall sharply due to geopolitical easing, filament's independent trend may be dragged down, as reduced cost support would limit gains.