Why is acetic anhydride price volatility so closely tied to acetic acid supply?

Why is acetic anhydride price volatility so closely tied to acetic acid supply?
Acetic anhydride pricing is fundamentally feedstock-driven, with acetic acid as the dominant cost input. Recent market data shows that when acetic acid prices surged over 75% from mid-January, acetic anhydride followed suit, breaking the 10,000 yuan/ton mark in April—a historic high—up 10.16% within two weeks. Supply disruptions at major acetic acid producers, including unplanned outages and uncertain restart schedules, tightened feedstock availability and pushed costs higher. Conversely, when acetic acid prices fell sharply—dropping 27.18% in one month amid weak crude oil and broad chemical sector declines—acetic anhydride prices also corrected, falling 13.16% to around 7,425 yuan/ton. This correlation underscores that acetic anhydride buyers should monitor acetic acid plant operations and inventory levels as leading indicators for price direction.