What Is Equity in Banking? Capital Rules, Ratios, and Home Equity

Equity in banking is what’s left of a bank’s assets after you subtract everything the bank owes. It belongs to the shareholders, and it’s the cushion that absorbs losses before depositors or taxpayers do. The same word also describes a homeowner’s stake in their house once the mortgage is subtracted from its value. Both meanings share the same math, and both matter to how banks are run, regulated, and used.

What Equity Means on a Bank’s Balance Sheet

Every bank’s balance sheet follows the standard accounting equation: assets equal liabilities plus shareholders’ equity.¹ For a bank, assets are mostly loans, securities, and cash reserves. Liabilities are mostly customer deposits and borrowed funds. What’s left after subtracting liabilities from assets is equity, sometimes called net assets or book value.

Shareholders’ equity is built from several components. The largest are usually retained earnings — accumulated profits the bank has not paid out as dividends — and common stock plus any capital surplus, meaning the amount investors paid above the par value of shares when the stock was issued.² Other pieces include preferred stock, treasury stock (shares the bank has repurchased, which reduce equity), and accumulated other comprehensive income, or AOCI, which captures unrealized gains and losses on certain investments.³

AOCI became a familiar term in 2023, after the failures of Silicon Valley Bank and other regional institutions. When interest rates rose sharply, the market value of banks’ bond portfolios fell. Banks that classified those bonds as available for sale had to record the unrealized losses through AOCI, which reduced their reported equity. Banks that classified bonds as held to maturity kept them at original cost on the books, masking the decline.⁴ Silicon Valley Bank held roughly 46% of its total assets in held-to-maturity securities, and unrealized losses on that portfolio alone grew from about $1.3 billion at the end of 2021 to $15.2 billion a year later, dwarfing the bank’s $15.5 billion in total equity capital.⁵ When the bank was forced to sell securities to meet withdrawals, paper losses became real ones and the equity buffer effectively vanished.

Why Banks Need So Much of It

Banks are far more leveraged than most businesses. A typical non-financial company might fund half its assets with equity and half with debt. A bank might fund only 5% to 15% of its assets with equity, financing the rest through deposits and borrowings. That leverage magnifies returns in good times, but it also means a modest decline in asset values can threaten solvency. Equity is what stands between a bad quarter and a failed bank.

Higher equity levels do more than absorb losses. They give managers and owners greater skin in the game, which discourages reckless risk-taking and encourages better screening of borrowers. FDIC research has found that a one-percentage-point increase in the equity-to-assets ratio is associated with a 0.6% to 1.69% increase in new loan growth, meaning well-capitalized banks actually tend to lend more, not less.⁶

There is an ongoing debate about cost. Equity investors demand higher returns than depositors or bondholders, and empirical estimates suggest a 10-percentage-point increase in the book equity ratio is associated with a 54 to 92 basis point rise in a bank’s cost of capital.⁶ Tax policy pushes in the same direction: interest payments on debt are deductible while dividends to equity holders are not, giving banks a built-in incentive to prefer debt.

The Minimum Amounts Regulators Require

Because highly leveraged institutions back deposits insured by the government, regulators set floors for how much equity a bank must hold. The international framework is the Basel Accords, developed by the Basel Committee on Banking Supervision.

How Basel III Tiers Capital

Basel III sorts bank capital into tiers based on how readily each layer can absorb losses.

Common Equity Tier 1, or CET1, is the highest-quality capital. It consists of common shares, retained earnings, and certain comprehensive income items, and must be available for “unrestricted and immediate use” to cover losses.⁷ Goodwill, other intangibles, and some deferred tax assets are deducted from CET1 because they have limited value in a crisis.⁸

Additional Tier 1 covers hybrid instruments, such as contingent convertible bonds, that can be written down or converted to common equity if a bank’s CET1 ratio falls below a trigger. Tier 2 covers subordinated debt and similar instruments that absorb losses only if a bank fails outright.

Under Article 92 of the EU Capital Requirements Regulation, the minimum CET1 ratio is 4.5% of risk-weighted assets, the minimum Tier 1 ratio is 6%, and the minimum total capital ratio is 8%.⁷ Banks typically hold well above those floors. European banks supervised by the European Central Bank reported an average CET1 ratio of 16.1% as of mid-2025, against an aggregate requirement and guidance level of 11.2% for 2026.⁹ Large banks globally averaged a CET1 ratio of 13.9% at mid-2025.¹⁰

What Happens When a U.S. Bank Falls Short

In the United States, the FDIC’s Prompt Corrective Action framework converts capital ratios into concrete consequences. Banks are sorted into five categories, and each triggers progressively more severe intervention.¹¹

A well-capitalized bank has a CET1 ratio at or above 6.5%, a Tier 1 ratio at or above 8%, a total capital ratio at or above 10%, and a leverage ratio at or above 5%.¹² An adequately capitalized bank meets the minimums (CET1 of 4.5%, Tier 1 of 6%, total capital of 8%, leverage of 4%) without clearing them by much.

An undercapitalized bank falls below any of those minimums. It must submit a capital restoration plan within 45 days and faces restrictions on growth, branching, and new business lines. A significantly undercapitalized bank falls well below the minimums; regulators can force it to sell shares, cap executive compensation, or dismiss officers and directors. A critically undercapitalized bank, meaning one whose tangible equity has dropped to 2% or less of total assets, must generally be placed into receivership or conservatorship within 90 days.¹³

Revised Basel III proposals issued jointly by the Federal Reserve, FDIC, and OCC in March 2026 would also require banks above $100 billion in assets to include unrealized gains and losses on available-for-sale securities in their regulatory capital, expanding AOCI recognition well beyond the nine largest holding companies currently covered.¹⁴ FDIC Chairman Martin Gruenberg said that if Silicon Valley Bank had been subject to that requirement, the weakened capital position would have been visible earlier and the loss of market confidence that triggered the run might have been averted.¹⁵

How Investors Judge a Bank by Its Equity

Because banks run on leverage, equity-based ratios do more valuation work for them than for most industries. Two measures dominate.

Return on Equity

Return on equity, or ROE, measures how effectively a bank turns shareholder equity into profit. It is calculated as after-tax net income divided by average equity.¹⁶ In early 2026, U.S. money-center banks posted an average ROE of roughly 12.9%, while regional banks averaged about 9.8%.¹⁷ European banks recorded an aggregate ROE of 10.7% in the second quarter of 2025.¹⁸ A bank that consistently earns an ROE above its cost of equity, generally estimated at 10% to 12%, is considered to be creating value for shareholders.

Price-to-Tangible Book Value

Tangible book value, or TBV, strips goodwill and other intangible assets out of shareholders’ equity, leaving only the hard assets that would survive a liquidation. Goodwill is deducted because under Basel III it has zero value for regulatory capital purposes and would be written off to zero if a bank were wound down. The price-to-tangible-book-value ratio compares a bank’s stock price to its TBV per share. A ratio above 1.0 signals that investors expect the bank to earn more than its cost of equity. A ratio below 1.0 says the market thinks the bank is destroying value. In late 2025, large money-center banks traded at 1.5 to 3.0 times TBV, well-run regional banks at 1.0 to 2.0 times, and underperforming or distressed banks often below book value.

Home Equity: What the Word Means for Consumers

For most individuals, equity in a banking context means home equity: the difference between a home’s current market value and the outstanding mortgage balance.¹⁹ A $400,000 home with a $250,000 mortgage carries $150,000 in equity. It’s a major component of household net worth, though it isn’t liquid until the home is sold or borrowed against.

Homeowners build equity in two ways: by paying down mortgage principal and through appreciation in the home’s market value. Freddie Mac puts the long-run national average for home appreciation at about 3% per year.²⁰ Equity can also decline if property values fall or if the owner takes on more debt secured by the home.

Ways to Borrow Against It

A home equity loan is a lump-sum second mortgage with a fixed interest rate, repaid over a term of typically 5 to 30 years.²¹ A home equity line of credit, or HELOC, is a revolving credit line with a draw period, usually 5 to 10 years, followed by a repayment period, and interest rates are usually variable.²² A cash-out refinance replaces the existing mortgage with a larger one and pays the difference to the homeowner in cash.¹⁹

Lenders generally require at least 15% to 20% equity in the home, a credit score of 680 or higher, and a debt-to-income ratio below 43%. Closing costs run 2% to 5% of the loan amount.²¹ Because both products use the home as collateral, default can lead to foreclosure.²³

Consumer Protections You Have

The Truth in Lending Act requires lenders to disclose annual percentage rates, payment terms, and all associated costs at the time of application.²⁴ After closing on a home equity loan or HELOC secured by a primary residence, you have a three-business-day right of rescission that lets you cancel for any reason without penalty.²³ The Home Ownership and Equity Protection Act of 1994 adds protections for high-rate and high-fee loans, prohibiting features like negative amortization, balloon payments on terms under five years, and lending based solely on collateral value without regard to the borrower’s ability to repay.²⁵

When Equity Turns Negative

Negative equity, sometimes called being underwater, occurs when the balance owed on a mortgage exceeds the home’s current market value. It usually results from a decline in property values, as happened on a massive scale during the 2008 housing crisis, or from borrowing a large amount with a small down payment.²⁶ Homeowners in negative equity have difficulty refinancing or selling without absorbing a loss.

Predatory lenders have historically targeted vulnerable homeowners to strip accumulated equity. Common schemes include writing loans the borrower clearly cannot afford so that foreclosure captures the equity, repeated unnecessary refinancing that generates fees while increasing debt, and persuading distressed homeowners to sign over deeds under false promises of foreclosure relief.²⁷ Under TILA, a successful borrower can recover actual damages plus twice the finance charge or statutory penalties, and a court can order the return of all money paid and release of any security interest on the home.

Equity as Fair Access to Banking

The word equity also carries a social meaning in banking: fair and equal access to financial services. The Community Reinvestment Act, enacted in 1977, was designed to combat redlining, the practice by which banks refused to lend in predominantly minority or low-income neighborhoods. The CRA requires federally insured banks to meet the credit needs of their entire communities, and regulators rate each institution’s performance; poor ratings can block applications for mergers, acquisitions, and new branches.²⁸

The CRA works alongside the Equal Credit Opportunity Act and the Fair Housing Act, which prohibit lending discrimination based on race, ethnicity, gender, and other protected characteristics. Regulators who find a pattern or practice of discrimination must refer the matter to the Department of Justice.²⁸ The history explains why these laws exist: between 1934 and 1969, while the national homeownership rate climbed from 44% to 63%, fewer than 1% of African Americans were able to obtain a mortgage, a legacy of explicit government-backed racial market segmentation.²⁹

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