Resin Pricing Indexes Explained: What Resin Buyers Need to Know

You're probably overpaying for resin. Not because you're bad at negotiating, but because you're locked into an index that moves one way: up.

This isn't just about a few cents per pound. When indexes lag behind true market conditions—or worse, systematically favor suppliers—the impact ripples through your entire operation.

Yet, indexes dominate the industry. They set contract terms, anchor negotiations, and give finance teams numbers to plug into forecasts. Everyone uses them. It's how business gets done.

But recent volatility has exposed just how costly the status quo has become. Publication lags, methodology questions, and non-market adjustments can leave you flying blind when markets shift.

Today, we’re breaking down the facts, explaining how pricing indexes actually work, who provides them, and where they genuinely help. More importantly, we'll reveal their blind spots and show how procurement teams are supplementing indexes with real-time market signals and transparent pricing data. Because accepting that status quo isn't your only option anymore.                                                               

What Are Resin Pricing Indexes? Why Do They Matter?

Unlike commodities with transparent exchanges like crude oil or corn, resin trades in the shadows. No centralized market. No public price ticker. Just buyers, sellers, and a lot of private negotiations.

Enter pricing indexes. They're the industry's attempt to create order from chaos.

At their core, resin indexes track price movements across major categories like polyethylene (PE) and polypropylene (PP). Publishers survey suppliers, buyers, and traders, then compile that data into weekly or monthly benchmarks. It's not perfect transparency, but it beats flying completely blind.

These indexes matter because they've become the backbone of contract pricing. When you sign an index-plus deal, you're agreeing to pay whatever CDI or ICIS says, plus a negotiated margin. Index-minus is the same concept, with a discount baked in. Without these reference points, every price discussion would start from scratch.

The reach goes beyond individual contracts. Packaging giants use indexes to forecast material costs. Automotive suppliers build them into multi-year pricing models. Consumer goods companies rely on them for quarterly accruals. From budgeting to supplier negotiations, indexes touch every corner of procurement planning.

The problem? These indexes were designed for stability, not speed. They assume rational markets, gradual changes, and good-faith reporting. Today's reality tells a different story.                                                                                                                                                                                                     

Who Provides Resin Pricing Indexes?

Not all indexes are created equal. Each provider brings different methodologies, data sources, and regional strengths to the table. Understanding who's behind the numbers helps you evaluate what you're really buying into.                                                                                                            

Chemical Data (CDI) 

CDI holds the distinction of being one of North America's oldest resin pricing authorities. For decades, their weekly price assessments have anchored supplier contracts across the continent. Walk into any negotiation, and there's a good chance someone's quoting CDI numbers.

The company now operates under ICIS after a strategic acquisition, but the CDI brand remains deeply embedded in industry contracts. Many buyers don't even realize their "CDI pricing" now comes from a global chemical intelligence giant.                                             

ICIS

As the parent company of CDI, ICIS brings serious scale to resin market intelligence. They track everything from commodity-grade polyethylene to specialty engineering resins across global markets.

Beyond basic pricing, ICIS offers forward curves, market forecasts, and analytical commentary. Their global reach means they can connect Asian market movements to North American pricing, providing valuable context when supply chains span continents.              

Other Notable Sources

The resin pricing landscape extends beyond traditional indexes:

CMAI deserves mention as a historic player. Once a major index brand, it's now part of IHS Markit (S&P Global), another reminder of ongoing consolidation in the pricing intelligence space.

Plastics News publishes weekly spot pricing summaries that procurement teams regularly cross-reference against index prices. Their reports offer a quick market pulse, though they lack the contractual weight of formal indexes.

The Plastics Exchange operates as a spot trading platform for commodity resins, offering real-time transaction data. Their ResIntel product adds curated market analysis and pricing benchmarks based on actual deal flow.

Platts/S&P Global Commodity Insights offers global polymer pricing and benchmarks for resins and feedstocks. Often used in international or upstream sourcing, some buyers use it to supplement CDI or ICIS.                                                                                                                      

Pros of Using Traditional Resin Pricing Indexes

Despite their limitations, indexes endure for good reasons. They solve real problems that procurement teams face every day.

• Established Credibility – When you reference CDI or ICIS pricing in a supplier meeting, nobody questions what those numbers mean. That shared understanding has value. It eliminates the "he said, she said" dynamic that could otherwise dominate price discussions. Both parties work from the same baseline, even if they disagree on the premium or discount.
• Contract Stability – Rather than renegotiating prices every quarter, index-linked deals adjust automatically. This predictability helps both buyers and suppliers plan ahead. Finance teams can model costs. Operations can budget for materials. Sales can quote customers with some confidence about margin protection.
• Historical Benchmarking – Three years of index data strengthens any negotiation. You're not just claiming prices should drop—you're demonstrating market patterns. That data becomes particularly powerful when you're pushing back against increases that outpace index movements. Suppliers can't dismiss documented trends.
• Internal Alignment – Procurement and finance need to speak the same language about material costs. When both teams reference the same index, budget discussions become clearer. Variance analysis makes sense. Accruals match market reality—or at least a version of it everyone agrees on.
• Stability in Calm Markets – During stable periods, these benefits multiply. When prices move gradually and predictably, indexes work exactly as designed. They simplify complex market dynamics into manageable numbers. They reduce negotiation friction. They keep everyone focused on running the business rather than arguing about pricing methodology.

The issue isn't whether indexes have value. They do. The question is whether that value holds up when markets turn volatile.

Limitations and Challenges Buyers Should Understand

Every tool has its blind spots. With resin indexes, those limitations can cost you real money.

• Survey Data, Not Transaction Reality – Most indexes rely on voluntary surveys submitted by market participants. Suppliers report their "asking prices." Buyers share what they "expect to pay." But actual transaction data? That's rarely part of the equation.
• Black Box Methodology – Good luck finding out exactly how your index calculates its weekly price. Most providers guard their methodologies like state secrets. They'll tell you they survey "market participants" and use "proprietary weighting," but the actual math remains hidden.
• Publication Lag in Fast Markets – Weekly or monthly index updates made sense when markets moved slowly. But today, prices can shift dramatically in days. By the time that monthly index publishes, the spot market might have already reversed course.
• Non-Market Adjustments (NMAs) – Nothing frustrates buyers quite like NMAs. These "corrections" appear when index publishers decide their numbers have drifted from market reality. The adjustment might be 3 cents, 5 cents, even more, and applied retroactively.
• Missing Market Nuances – Indexes paint with broad brushes, flattening a complex market into simple numbers. In the process, they miss critical details:
• Index Confusion – Pull up CDI, ICIS, and IHS pricing for the same resin grade. Notice anything strange? They rarely match. Different surveys, different methodologies, different results.                                                                                                                                                                    

How Index-Based Pricing Impacts Finance and Procurement Strategy

When indexes miss the mark, the pain spreads company-wide. But two areas in particular tend to feel that pain more acutely than others: finance and procurement.                                                                                                                                                                                                                                           

Finance Teams

Finance builds the entire cost structure around index projections. They use these numbers to forecast resin COGS, set margin targets, and calculate monthly accruals. It's the foundation of their financial planning.

So, when indexes miss the mark, the dominoes start falling. That 3-cent lag in reported prices? It shows up as a massive variance in the monthly P&L. Suddenly, procurement is explaining why actual costs blew past budget, even though they bought exactly as planned.

The misalignment gets worse during volatile periods. Finance books accruals based on the published index. Procurement pays actual market prices. When those numbers diverge, it creates friction between teams that should otherwise be aligned. Finance thinks procurement overpaid. Procurement knows they got market rate. The index sits in the middle, helping neither.                                    

Procurement Teams

From a procurement perspective, index-linked contracts sound efficient until you realize what you've given up. When price is tied to "CDI plus 2 cents," that 2-cent delta becomes your only negotiation point. Everything else is predetermined by the index.

This structure makes buyers reactive by design. You can't anticipate market moves. Instead, you wait for the index to tell you what happened. In other words, there’s no competitive dynamics to leverage—the index is the index. Strategic sourcing becomes tactical damage control.

The real danger comes from gradual margin erosion. Indexes might creep up 1 cent here, 2 cents there. No single increase triggers alarm bells. But compound those movements over two years, and you've lost significant margin. By the time sirens blare, the damage is done.

Worse, this drift often goes unchallenged because "that's what the index says." The very tool meant to simplify pricing becomes a shield for systematic price increases.                                                                                                                                                                                                                         

What Strategic Procurement Teams Are Doing Differently

The gap between average and exceptional procurement teams isn't negotiation skill. It's data sophistication.

While most buyers wait for monthly index updates and react to supplier announcements, a growing number are flipping the script. They're tapping into real-time market signals and predictive analytics to see changes coming, not after they've already hit.

• Validating Indexes Against Reality
• Building Historical Intelligence
• Layering Predictive Analytics
• Engineering Data-Driven Contracts
• Accelerating Organizational Speed

The transformation is complete when indexes become just one input in a sophisticated analytics engine. While others react to monthly publications, data-driven teams are already positioned for what's next.                                                                                                                           

How to Use Resin Indexes More Effectively

Not every team can overhaul their pricing strategy overnight. Budget constraints, contract commitments, and organizational inertia are real. But you don't need a complete transformation to get more value from indexes.

• Know Your Supplier's Update Rhythm
• Decode the Application Method
• Track Your Reality vs. Their Claims
• Treat Indexes as a Starting Point
• Find Additional Benchmarks

The goal isn't perfection. It's progress. Each small improvement in how you use indexes translates directly to margin protection.                 

The Future of Resin Price Discovery

The resin market is at an inflection point. After decades of index dominance, buyers are demanding—and getting—something better.

Indexes aren't disappearing. But their monopoly on price discovery is over. Today's buyers supplement monthly surveys with real-time transaction data, predictive analytics, and verified benchmarks. They see changes coming instead of reacting to last month's news.

The gap between data-driven buyers and index-dependent ones will only widen. In a market where pennies per pound translate to millions in margin, speed and accuracy compound quickly.

The question isn't whether to evolve beyond pure index reliance. It's how quickly you can make the shift.                                                                   

See What Modern Resin Intelligence Looks Like

Still timing purchases based on monthly index reports?

You don't have to accept pricing disconnects as the cost of doing business. ResinSmart combines real-time market signals with expert guidance to help you spot when indexes miss the mark, and capture the savings others leave on the table.

Schedule a demo today and get the market visibility you need to challenge unfair increases with confidence. Because accepting index prices at face value used to be a necessity. Now it’s a choice.