Historical cost and fair value are two ways of putting a number on the same asset. Historical cost is what the company actually paid to acquire it, recorded from invoices and held on the books at that figure (adjusted only for depreciation or impairment). Fair value is what the asset would sell for today in an orderly market transaction. Both US GAAP and IFRS use a mixed-measurement model, applying historical cost to some balance sheet items and fair value to others, so the choice between historical cost vs fair value is rarely up to the company. It depends on the type of asset and the standard that governs it.
How Historical Cost Works
Historical cost captures every expenditure needed to get an asset ready for use. A machine purchased for $90,000 that requires $7,000 in shipping and installation goes on the books at $97,000. The figure ties back to contracts and invoices, which makes it objective and auditable.
For long-lived assets like equipment or buildings, that cost is then spread across the asset’s useful life through depreciation. The $97,000 machine depreciated straight-line over ten years produces a $9,700 annual expense, and the carrying amount on the balance sheet drops by the same amount each year. The asset stays at that adjusted cost until it is sold, retired, or written down. Management cannot revalue it upward simply because the market has moved.
Stability is the method’s chief virtue. Statements prepared on a historical cost basis are consistent from period to period, and auditors can trace every figure to a document. The limitation is equally obvious. Land bought in 1985 for $200,000 may sit on the balance sheet at that figure while its market value has grown many times over. Historical cost tells you what the company paid, not what it owns in economic terms today.
How Fair Value Works
Fair value is defined as the price that would be received to sell an asset, or paid to transfer a liability, in an orderly transaction between market participants at the measurement date. Both US GAAP and IFRS use this identical definition, anchored in an exit price rather than an entry cost.1IFRS Foundation. IFRS 13 Fair Value Measurement The word “orderly” matters. Fire-sale prices and forced liquidations don’t count. The standard assumes a hypothetical transaction in the asset’s principal market, meaning the market with the greatest volume and activity for that item.
The appeal of fair value is relevance. If a bank holds a bond portfolio, investors care more about what those bonds are worth today than what the bank paid three years ago. The trade-off is subjectivity. Not every asset trades on an exchange, and estimating an exit price for an illiquid item requires judgment.
The Fair Value Hierarchy
To manage that subjectivity, both ASC 820 under US GAAP and IFRS 13 sort valuation inputs into three tiers.1IFRS Foundation. IFRS 13 Fair Value Measurement
- Level 1 inputs are quoted prices for identical items in active markets. A publicly traded stock with a closing price on an exchange is the textbook example. These require no adjustment and are the most reliable.
- Level 2 inputs are observable prices for similar items, or for identical items in less active markets. A corporate bond that doesn’t trade daily but can be priced from yield curves, benchmark rates, or quotes on comparable bonds falls here. The data is market-based but modeled.
- Level 3 inputs are unobservable and rely on the company’s own assumptions. When there is little or no market activity, the entity builds a valuation model using internal projections such as discounted cash flows. These are the least reliable measurements and require the most judgment.
A company with a large share of assets at Level 3 is effectively grading its own homework, and small shifts in assumptions can move the reported numbers materially.
Which Items Get Which Treatment
Accounting standards assign the measurement basis based on the nature of the item.
Assets Kept at Historical Cost
Property, plant, and equipment is the flagship cost-basis category under US GAAP. Buildings, machinery, and vehicles are recorded at acquisition cost, depreciated over their useful lives, and tested for impairment if warning signs appear. Land is carried at cost as well, but is not depreciated.
Inventory follows a modified cost approach. Under ASC 330, inventory is measured at the lower of cost or net realizable value.2FASB. ASU Inventory Topic 330 – Simplifying the Measurement of Inventory If a product can only be sold for less than the company paid, the carrying amount is written down and the loss is recognized immediately. Cost is the starting point, but market deterioration forces a downward adjustment.
Purchased intangible assets such as patents and customer lists are recorded at cost and amortized over their useful lives. Internally generated intangibles, like a brand built through advertising, generally cannot be capitalized.
Assets Marked to Fair Value
Financial instruments dominate the fair value side of the balance sheet. Equity securities with readily determinable fair values are carried at fair value, with changes flowing through net income. Debt securities classified as trading are also marked to fair value through net income each period.
Derivatives (swaps, futures, options) are always recorded at fair value. Their values shift rapidly, and the cost of entering a derivative is often zero, which makes historical cost meaningless as a measurement basis.
The Fair Value Option
ASC 825 gives companies a limited election. For most financial instruments that would otherwise be measured at cost or amortized cost, the entity can irrevocably choose fair value measurement on an instrument-by-instrument basis. A bank might elect the fair value option for a specific loan portfolio to reduce an accounting mismatch with related hedging instruments while keeping similar loans at amortized cost. The election is made at inception and cannot be reversed, so it is used selectively.
Where Fair Value Changes Land
A common misconception is that all unrealized gains and losses hit net income. They don’t. The destination depends on how the item is classified.
Straight Through Net Income
Fair value changes on trading securities, derivatives not designated as hedging instruments, and equity securities with readily determinable fair values run through the income statement each period. Before 2018, companies could classify equity investments as available-for-sale and park the unrealized gains in other comprehensive income. ASU 2016-01 closed that door: equity securities now run through earnings.
Through Other Comprehensive Income
Debt securities classified as available-for-sale get different treatment. Their unrealized gains and losses bypass the income statement and are reported in other comprehensive income (OCI), a separate component of shareholders’ equity. The fair value adjustment still appears on the balance sheet, but it doesn’t affect reported earnings until the security is sold or impaired. The logic is that a company holding bonds to collect interest shouldn’t see earnings whipsawed by day-to-day price movements it has no intention of realizing.
The distinction matters. Two companies with identical bond portfolios can report very different earnings because one classified its holdings as trading and the other as available-for-sale.
Impairment: Where Historical Cost Meets Fair Value
Historical cost is not a one-way street upward, and this is where the two models intersect. When a long-lived asset’s value drops below its carrying amount, fair value steps in to cap the loss.
Under ASC 360, a company must test a long-lived asset for impairment whenever events suggest the carrying amount may not be recoverable. If the asset fails a recoverability test, the impairment loss is measured as the difference between carrying amount and fair value. The write-down is permanent under US GAAP. Even if the asset later recovers in value, the company cannot reverse the impairment.
Goodwill works similarly. It arises when one company acquires another for more than the fair value of the identifiable net assets, is recorded at historical cost at the acquisition date, and is not amortized. Instead, it is tested for impairment at least annually by comparing the fair value of the reporting unit to its carrying amount. If the carrying amount is higher, goodwill is written down by the difference.3FASB. Goodwill Impairment Testing Large goodwill impairments regularly make headlines because they signal that an acquisition has underperformed.
The takeaway: historical cost sets the ceiling, but fair value determines the floor. Every major asset on the balance sheet is subject to some form of fair value check, even when it isn’t routinely marked to market.
How IFRS Handles the Same Question
IFRS and US GAAP share the fair value definition and the hierarchy, but IFRS allows more room to use fair value for items US GAAP keeps at cost.
The Revaluation Model for PP&E
Under IAS 16, a company can choose to carry an entire class of property, plant, and equipment at revalued amounts rather than at historical cost. Once elected, those assets are periodically remeasured to fair value, and the carrying amount is adjusted.4IFRS Foundation. IAS 16 Property, Plant and Equipment US GAAP does not permit this. A US company’s factory stays at depreciated cost regardless of how much the surrounding real estate market has risen.
The accounting for revaluation swings under IFRS is asymmetric. An upward revaluation is recognized in OCI and accumulated in a revaluation surplus within equity. A downward revaluation is charged to profit or loss unless a prior surplus exists for that asset, in which case the decrease first reduces the surplus.4IFRS Foundation. IAS 16 Property, Plant and Equipment The result is a balance sheet closer to current value with earnings partially shielded from upward volatility.
Financial Instruments Under IFRS 9
IFRS 9 classifies financial assets into three measurement categories based on the entity’s business model and the asset’s cash flow characteristics: amortized cost, fair value through OCI, and fair value through profit or loss.5IFRS Foundation. IFRS 9 Financial Instruments Debt instruments held to collect contractual cash flows go to amortized cost. Those held in a mixed model, where the entity both collects cash flows and sells, go to fair value through OCI. Everything else runs through profit or loss. The business-model test under IFRS is more explicit than the US GAAP approach, which relies on classification elections at acquisition.
Crypto Assets: A Recent Move to Fair Value
Until recently, companies holding Bitcoin or similar crypto had to treat them as indefinite-lived intangible assets measured at cost, written down for impairment but never written up when prices recovered. A company that bought Bitcoin at $30,000, watched it fall to $20,000, and then saw it climb to $60,000 was stuck carrying it at $20,000. The accounting lagged economic reality by design.
ASU 2023-08 changed this for fiscal years beginning after December 15, 2024, meaning it is fully in effect for calendar-year 2025 and 2026 reporting. Crypto assets meeting certain criteria (fungible, residing on a blockchain, not issued by the reporting entity) must now be measured at fair value each period, with gains and losses recognized in net income. The standard also requires crypto gains and losses to be presented separately from changes in other intangible assets.
What This Means for Reading Financial Statements
A company whose assets are mostly PP&E and inventory will report a stable but potentially stale balance sheet. Land, buildings, and equipment sit at depreciated cost regardless of market appreciation. Anyone performing an asset-based valuation of such a company has to adjust the reported figures using appraisals or comparable transactions.
A company whose assets are mostly financial instruments will report a balance sheet that moves with the markets. A trading desk’s bond portfolio updates daily. The snapshot is more current, but the balance sheet can look dramatically different from one quarter to the next without any change in operations.
The income statement follows the same pattern. Historical cost keeps recurring charges predictable: depreciation and amortization are set by formula at acquisition, and gains or losses appear only when the company actually sells something. Fair value measurement introduces unrealized gains and losses that can dwarf operating results. A financial institution might report strong loan performance but weak earnings because its trading portfolio dropped in value. These fair value adjustments are often non-cash and may reverse the following period. Distinguishing operational trends from market noise means paying close attention to which gains are realized versus unrealized, and which run through net income versus OCI.
Neither model wins cleanly. Historical cost prioritizes reliability: verifiable, consistent, resistant to manipulation. Fair value prioritizes relevance: current, market-based, useful for pricing decisions. The mixed-measurement system used by both frameworks reflects a working compromise. Operational assets stay at cost because their value comes from use, not sale. Financial instruments go to fair value because their value comes from market pricing. Impairment rules make sure cost-basis assets are never carried above what they can recover. The hierarchy, the disclosures, and the OCI classifications give readers the tools to judge how much of a company’s reported numbers rest on documented transactions and how much rests on estimates.