On August 31, the polyester filament market witnessed a dramatic sentiment reversal. The average sales-to-production ratio of sample enterprises jumped from 34.7% the previous trading day to 82.8%, a single-day increase of 48.1 percentage points—far beyond the normal fluctuation range, signaling a cost-driven concentrated restocking wave. Notably, the distribution of that day's data was highly uneven, ranging from 40% to 260%, reflecting widening divergence between leading producers and smaller mills.
Cost Transmission and Stock-Holding Psychology
The abnormal surge in the sales ratio was not a sign of fundamental demand recovery but a pulse-like transaction triggered by changing cost expectations. After upstream raw material prices strengthened, polyester filament producers generally adopted a strategy of holding stocks at low prices, preferring to reduce shipments rather than sell at a loss. This mentality was directly reflected in quotations—some specifications were suspended in the afternoon, intensifying market tension.
Downstream users' concern about rising future procurement costs was the direct driver of this restocking. Under the expectation of price hikes, weaving enterprises no longer waited for lower prices but conducted small, frequent trial purchases. The 260% ratio likely came from a few large mills selling to core customers, while the 40% low-end samples indicate that a considerable number of small and medium factories remained cautious, waiting for clearer cost signals.
Signals Behind the Data
A 48-point jump in the sales ratio is rare in the chemical fiber industry. It conveys at least three industrial signals. First, cost-based pricing logic has reasserted dominance—when raw material price increases exceed a threshold, filament prices no longer follow supply-demand dynamics but passively shift along the cost curve. Second, inventory structures along the chain are improving; downstream restocking helps alleviate polyester plants' finished-goods inventory pressure, creating room for further price increases.
Third—and most noteworthy—market sentiment is recovering faster than actual demand. Although an 82.8% ratio is close to the industry boom line (typically above 85% is considered balanced-to-strong), without terminal order support, such expectation-driven restocking is unlikely to sustain. Historical experience shows that cost-driven rallies often end with a pattern of "pulse-up followed by rapid correction," unless demand improves within the following two weeks.
Industrial Impact and Regional Divergence
From a regional perspective, factories in major filament-producing areas such as Shengze and Changxing accelerated shipments, with some enterprises maintaining ratios above 100% for two consecutive days. In contrast, emerging polyester clusters in northern Jiangsu and Anhui showed more moderate price follow-through, reflecting differences in cost-pass-through ability—larger enterprises with stable customer bases can better transfer cost pressure downstream.
For weaving enterprises, the current restocking window presents both opportunity and risk. If they stock up heavily at the cost peak, a subsequent raw material price decline could lead to inventory depreciation and capital strain. A more rational approach is to purchase in batches, maintain raw material inventory at a safe level of 7–10 days, and strengthen locking of finished product orders to prevent raw material volatility from eroding processing margins.