Updated for the 2026-2027 CFA® Level I curriculum.
Forecasting revenue and costs is not just extending a trend line. An analyst also has to ask whether a company can actually get away with raising prices, or whether suppliers and customers will squeeze its margins instead. Porter's five forces gives you a structured way to answer that question. On the Level I exam, you need to connect each force to a specific direction: does it support higher prices, lower costs, or does it work against the company on either side of the income statement?
Quick Answer
Porter's five forces analysis tells an analyst whether a company can raise prices or control costs in a forecast. A favorable competitive position (low buyer and supplier power, high entry barriers, few substitutes, moderate rivalry) supports higher price growth assumptions and stable margins. An unfavorable position limits pricing power or lets suppliers raise costs, so analysts lower price growth assumptions and raise cost growth assumptions in the model.
Key Takeaways
Porter's five forces assesses competitive position across five dimensions: threat of new entrants, bargaining power of buyers, bargaining power of suppliers, threat of substitutes, and rivalry among existing competitors.
Each force affects pricing power, cost structure, or both, when you build a forecast.
A favorable competitive position supports higher price growth assumptions and more stable gross margins.
A weak competitive position usually means lower price growth and margin compression because cost increases cannot be fully passed through to customers.
Buyer power and supplier power act on opposite sides of the income statement but can both compress margin.
Analysts translate a qualitative five forces assessment into quantitative price and cost growth assumptions inside a pro forma model.
What You Need to Know for CFA Level I
The LOS verb is "explain." Expect conceptual, scenario-based questions rather than heavy calculation.
Know each of the five forces and whether it typically increases or decreases a company's pricing power.
Know that supplier power pushes on cost (COGS side) while buyer power pushes on price (revenue side), and both can lower margin.
Understand the boundary with neighboring notes: this page covers competitive position effects on price and cost assumptions. It does not cover inflation-driven cost forecasting or the mechanics of building a sales-based pro forma statement.
Main trap to avoid: judging competitive position from a single force instead of weighing all five together.
What the LOS Is Asking You to Do
The exam expects you to take a short qualitative description of an industry or company, such as "three competitors, one key supplier, high switching costs," and translate it into a forecast direction. You are not computing market share or running a regression. You are deciding: does this competitive setup let the company raise prices, or does it force the company to absorb cost pressure?
This matters for modeling because a revenue forecast often starts with a price growth assumption, and a cost forecast often starts with a cost growth assumption. Five forces analysis is one input analysts use to set those two assumptions before they touch a spreadsheet.
The Five Forces and Their Effect on Price and Cost Assumptions
Each force pulls on price, cost, or both. The table below summarizes the typical direction of each effect.
Force | Effect When Favorable to the Company | Effect When Unfavorable to the Company | Forecast Assumption Affected |
|---|---|---|---|
Threat of new entrants | Low threat protects existing pricing | High threat caps price increases | Price growth |
Bargaining power of buyers | Low buyer power allows price increases to stick | High buyer power forces discounts or price concessions | Price growth |
Bargaining power of suppliers | Low supplier power keeps input costs manageable | High supplier power raises input costs with little pushback | Cost growth |
Threat of substitutes | Few substitutes support higher prices | Many substitutes cap price increases | Price growth |
Rivalry among existing competitors | Low rivalry limits price cuts and promotional spending | High rivalry pressures price cuts and raises marketing or promotional costs | Price growth and cost growth |
Notice that only supplier power acts directly on the cost side in most exam scenarios. The other four forces act mainly on pricing power, though intense rivalry can raise costs too, through promotional or marketing spending needed to defend market share.
Translating Competitive Position Into Forecast Assumptions
A single force rarely tells the full story. The exam usually gives you a short description touching on multiple forces, and you need the net effect.
Favorable Competitive Position
When most forces favor the company (high entry barriers, low buyer power, low supplier power, few substitutes, moderate or low rivalry), the company usually has pricing power. An analyst can reasonably assume price growth near or above general cost inflation, with gross margin holding steady or improving over the forecast period.
Unfavorable Competitive Position
When forces work against the company (low entry barriers, concentrated buyers, a dominant supplier, many substitutes, intense rivalry), pricing power is weak. An analyst should lower the price growth assumption below the rate of cost increases. This produces margin compression in the forecast, even if the company's absolute revenue still grows.
The key exam skill is reading a scenario, identifying which forces are present, and deciding whether the net effect supports or pressures the margin, then stating the correct direction for the price and cost assumptions.
Working Example
Vertex Components supplies machined parts to two large automakers, which together account for 80% of Vertex's sales. Vertex sources a critical raw material from a single approved supplier with no substitute input available. Three firms compete mainly on quality in a stable market. Customers face high switching costs, new suppliers need years of certification, and no technically viable alternative product meets the automakers' requirements. Assume flat sales volume and an unchanged input mix in the numerical forecast.
An analyst's naive base case assumes Vertex can raise prices 5% next year, matching expected input cost inflation of 5%, holding gross margin flat.
Step 1: Identify the forces.
Bargaining power of buyers: high. Two customers represent 80% of sales and can negotiate hard on price.
Bargaining power of suppliers: high. One approved supplier for a critical input, with no substitute.
Threat of new entrants: low. Design-in switching costs protect Vertex's existing business.
Threat of substitutes: low. No technically viable alternative to Vertex's product meets the customer requirements. The lack of a substitute input separately strengthens supplier power.
Rivalry: moderate. Three competitors, but switching costs limit active price competition.
Step 2: Determine the net effect.
High buyer power and high supplier power both work against Vertex, even though entry barriers and substitute threats are favorable. The buyers can resist price increases, and the supplier can still raise input costs regardless of what Vertex wants to charge.
Step 3: Revise the assumptions.
Because buyer power limits pricing power, the analyst caps price growth at 2% rather than 5%. Because supplier power is high, input cost growth stays at 5% regardless of Vertex's pricing outcome.
Step 4: Recalculate the forecast.
Naive base case (before five forces adjustment):
Five-forces-adjusted forecast:
The naive forecast assumed Vertex could raise selling prices by the same percentage as input costs, which produces a flat 30% margin. Once you factor in Vertex's weak position against concentrated buyers and a dominant supplier, the company cannot raise price fast enough to cover rising input costs. Gross margin compresses by roughly 206 basis points. The five forces assessment, not a change in the inflation rate, is what drives the margin change.
Common Exam Traps
Treating one force as decisive
A single favorable reading, such as low threat of new entrants, does not make the overall position strong if buyer and supplier power are both high. Weigh the net effect of all five forces together.
Confusing buyer power with supplier power effects
High buyer power limits price increases on the revenue side. High supplier power raises costs on the COGS side. Mixing up which side a force affects reverses the margin conclusion.
Ignoring rivalry's effect on costs, not just price
Intense rivalry can increase marketing or promotional spending, not only reduce price growth. Candidates who adjust price alone miss part of the forecast effect.
Confusing competitive position with general inflation forecasting
This LOS tests how competitive position affects the ability to set or absorb prices and costs. It does not test the mechanics of forecasting under rising or falling price levels generally, which is covered separately. A company can have strong pricing power and still face input cost inflation; these are two different forecast inputs.
Assuming a favorable position guarantees a price increase
A favorable five forces position only supports a higher price growth assumption. It does not guarantee that a company will raise prices in any specific forecast period.
Practice Question
An analyst is forecasting revenue and gross margin for Harmon Tools, a maker of specialized machine parts. Harmon faces three competitors, high switching costs for customers, a single approved supplier for a critical alloy, and no close substitute products. Based on a Porter's five forces assessment, which forecast adjustment is most appropriate?
Lower the price growth assumption because of high rivalry among existing competitors.
Raise the cost growth assumption because of high supplier bargaining power.
Lower the cost growth assumption because of low threat of substitutes.
Correct Answer: B
Harmon relies on a single approved supplier for a critical alloy with no substitute. This gives the supplier high bargaining power, allowing it to raise input prices with little resistance from Harmon. The correct forecast adjustment is to raise the cost growth assumption to reflect this supplier leverage.
Option A: Three competitors combined with high switching costs actually points to moderate, not high, rivalry. High switching costs reduce the price-cutting pressure typical of intense rivalry, so this is not the strongest supported adjustment.
Option C: Low threat of substitutes supports stronger pricing power, which would support a higher price growth assumption. It does not support a lower cost growth assumption. This choice confuses a pricing-side effect with a cost-side conclusion.
Continue Your CFA Level I Prep With KeyPoint
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FAQs About Porter’s Five Forces and Forecasting Prices and Costs
Do I need to memorize the names of all five forces for the exam?
Yes. You need to identify each force in a scenario and know its typical direction of effect on price or cost.
How is this different from forecasting costs under inflation?
Competitive position determines whether a company can pass cost increases through to customers. General inflation forecasting, covered in a separate note, deals with the input cost trend itself, not the company's ability to pass it on.
Can a company have strong pricing power and still see margin compression?
Yes. If a dominant supplier raises input costs faster than the company can raise prices, margin compresses even with strong pricing power on the revenue side.
Is this topic calculation heavy on the exam?
No. The LOS verb is "explain," so expect to interpret scenarios and identify forecast directions rather than perform complex calculations.
Does rivalry only affect pricing?
No. Intense rivalry can also raise costs, such as marketing or promotional spending needed to defend market share, in addition to limiting price increases.