Capital structure: what every ALM manager needs to know

Capital Structure: Core Concepts

Capital is not what most newcomers think it is. It's not the money in your bank account—it's the regulatory layer that protects depositors and creditors when things go wrong. Every dollar of capital your bank holds is a dollar that isn't being loaned out or invested, which is why capital is expensive and why ALM managers spend so much time thinking about optimization.

For ALM practitioners, capital structure matters because it directly shapes what you can do with the bank's balance sheet. Your lending capacity, investment portfolio size, dividend policy—all constrained by capital. Understanding capital structure means understanding the boundary conditions for everything else you do.

The Three Layers of Capital

Regulatory capital comes in tiers, each serving a different purpose:

Common Equity Tier 1 (CET1) is the purest form—common stock, retained earnings, and limited other instruments. CET1 absorbs losses first, so regulators demand more of it. It's also the most expensive from a shareholder perspective because equity investors demand returns.

Tier 1 Capital adds to CET1 with instruments like preferred stock and certain hybrid securities. These instruments have debt-like features (coupons, maturity) but can be written down in stress scenarios. They're cheaper than equity but more expensive than debt.

Tier 2 Capital includes subordinated debt and loan loss reserves. It absorbs losses second, so it's cheaper than Tier 1 but also less reliable. In a severe stress, Tier 2 is the first thing regulators will tell you to write down.

Why Your Bank's Capital Structure Matters

Your bank's capital structure directly affects:

• Dividend capacity: The more capital you hold, the more earnings you can return to shareholders
• M&A ability: Acquisitions require capital—a weak capital position means no growth optionality
• Risk appetite: Higher capital ratios give you breathing room to take calculated risks in lending and investments
• Cost of funding: Capital-constrained banks pay more for deposits and wholesale funding
• Competitive position: Well-capitalized banks win better assets in tight markets

This is why ALCO meetings always start with capital. Before you optimize duration, before you hedge, before you deploy the portfolio—you need to know your capital constraints.

The Numbers You'll See Every Day

Three key ratios appear in every regulatory report and earnings call:

• CET1 Ratio = CET1 Capital / Risk-Weighted Assets. This is the most stringent measure. Regulators mandate minimums here.
• Tier 1 Ratio = Tier 1 Capital / Risk-Weighted Assets. Slightly easier to meet than CET1 because it includes Tier 1 instruments.
• Total Capital Ratio = (Tier 1 + Tier 2 Capital) / Risk-Weighted Assets. The easiest to meet, and rarely the binding constraint.

Risk-weighted assets are the denominator—they adjust for credit risk across different asset types. A $100M residential mortgage (2% risk weight) counts as $2M towards RWA, while a $100M unsecured commercial loan (100% risk weight) counts as $100M.

Real Example: JPMorgan

Look at JPM's 10-Q. At the end of 2024, their CET1 ratio was around 12.5%, well above the regulatory minimum of 7%. This means they're not constrained on capital—they can grow assets, pay dividends, and return capital to shareholders. Compare that to a bank at 8.5% CET1 and you're looking at a bank that's essentially at the regulatory floor, unable to take material new risks without raising capital.

That one percentage point difference explains why JPM has strategic optionality that mid-cap banks don't have.

Capital Structure: The Full Picture

Why Capital Structure Is More Than Just Ratios

Capital structure is fundamentally about leverage and loss absorption. Your bank is a highly leveraged institution—typical total assets might be 10x tangible equity. That leverage is why capital matters so much. A 10% loss on assets would wipe out 100% of tangible equity. This is not theoretical: it happened to regional banks during 2023, and it's a constant stress scenario in bank modeling.

The regulatory capital framework was redesigned after 2008 specifically because banks didn't hold enough loss-absorbing capacity. Basel III moved the system toward higher capital requirements, more capital buffers above minimums, and capital that actually works (CET1) rather than accounting loopholes.

CET1: The Only Capital That Really Matters

When regulators stress-test a bank, they're asking: how much CET1 would this bank have after a 1-in-250-year loss event? That's the binding question. Tier 1 and Tier 2 are secondary—they matter for total capital ratios and for meeting regulatory minimums, but they're not what constrains your business.

CET1 consists of:

• Common stock: Par value of outstanding shares
• Retained earnings: Cumulative profits minus dividends paid
• Accumulated other comprehensive income (AOCI): Mostly unrealized gains/losses on available-for-sale securities
• Regulatory adjustments: Deductions for goodwill, intangibles, deferred tax assets, defined benefit pension deficits, and various other items

The adjustments are crucial. A bank with $5B in goodwill on the balance sheet has $5B deducted from CET1. This is why M&A can instantly destroy capital—you pay $2B for a bank, create $1.5B in goodwill, and that $1.5B is subtracted from your CET1. You need the deal to create enough earnings power to recover that lost capital capacity.

Real Example: The AOCI Trap

During 2022-2023, when rates rose rapidly, banks with large investment portfolios (mostly held-to-maturity securities) suffered massive unrealized losses. Those losses flowed through AOCI and directly reduced CET1.

A regional bank with a $50B investment portfolio invested in 2% coupon bonds, now trading at 20% discounts due to rate increases, had $10B in unrealized losses. That $10B (net of tax) hit AOCI and reduced tangible equity. Their CET1 ratio fell by 100+ basis points instantly, not because they lost money but because they marked their securities to market.

For a bank already at 8.5% CET1, a 100bp swing is material. That's why ALM managers obsess over duration, AOCI sensitivity, and the decision to be held-to-maturity vs. available-for-sale.

Risk-Weighted Assets: The Hidden Lever

Capital ratios have a denominator: RWA. Many banks optimize the numerator (raise more capital), but sophisticated ALM teams optimize the denominator too.

RWA is calculated as: Σ (Asset Balance × Risk Weight × Exposure Adjustment)

Different asset types have different risk weights under the standardized approach:

• Cash: 0% (no risk weight)
• US Treasury securities: 0%
• GSE-backed MBS: 20%
• Investment-grade corporates: 50-100% depending on rating
• Residential mortgages (secured): 35%
• Commercial mortgages: 50% or higher
• Unsecured commercial loans: 100%
• Equity holdings: 250-300%

A bank can improve its capital ratio by shifting assets from high-risk to low-risk categories. This happens in several ways:

1. Portfolio shifts: Sell higher-risk assets, buy lower-risk assets (e.g., shift from corporate bonds to Treasury securities). No capital raised, RWA decreased, ratio improved.

2. Risk mitigation: Hedge credit risks using credit derivatives, which can reduce the effective risk weight.

3. Securitization: Remove assets from the balance sheet via securitization, reducing RWA.

4. Loan sales: Sell loans that would otherwise occupy RWA space.

These aren't accounting gimmicks—they're legitimate ALM strategies. A bank with strong lending capabilities but limited capital will securitize mortgages to free up RWA for higher-return commercial loans.

The Leverage Ratio as a Hard Floor

Most ALM managers focus on risk-weighted capital ratios because risk weights capture economic reality. But there's also the leverage ratio: Total Tier 1 Capital / Total Assets (not risk-weighted).

The leverage ratio is typically 3-4% for banks. It's a blunt instrument—it doesn't differentiate between a low-risk Treasury and a high-risk unsecured loan. But precisely because it's blunt, it's an absolute floor. You can't optimize your way around it with risk weights.

A bank might have a 12% risk-weighted CET1 ratio but only a 4.5% leverage ratio. The leverage ratio would be the binding constraint, preventing asset growth even though risk-weighted ratios look comfortable.

Capital Modeling and Stress Testing

ALM teams build capital forecast models every quarter that project:

• Earnings power (net income minus expected loan losses)
• Dividend capacity
• Asset growth (limited by capital constraints)
• RWA evolution (based on loan portfolio changes, M&A, asset composition shifts)
• AOCI changes (from rate movements, credit spreads)

The model answers: "If we grow loans at X%, pay dividend Y%, and rates move Z%, what will our CET1 ratio be in 4 quarters?"

These models feed CCAR and DFAST stress testing, but they're used internally for everyday decision-making. Should we grow the mortgage portfolio? Only if earnings growth outpaces RWA growth. Should we increase the dividend? Only if capital ratios stay above target buffers.

Regulatory Minimums vs. Target Capital

Regulators set minimum capital ratios. For most large banks, CET1 minimum is 7%. But no bank operates at the minimum. Why?

1. Buffer for losses: A bank at exactly 7% CET1 can absorb almost no unexpected losses before becoming non-compliant.
2. Buffer for earnings volatility: A quarter of poor credit quality can swing ratios by 50bps.
3. Buffer for market stress: AOCI swings during rate volatility.
4. Business flexibility: You can't grow assets, make acquisitions, or increase shareholder returns when you're at the floor.

Most banks target CET1 ratios 200-350bps above the regulatory minimum. JPMorgan targets ~11%, regional banks might target 8.5-9.5%. These targets appear in investor presentations and guide quarterly ALCO decisions.

Capital Raising and Return of Capital

When a bank needs more capital, it can:

1. Retain earnings: Don't pay dividends, let retained earnings build capital. This is the cheapest and most flexible approach.
2. Raise equity: Issue common stock. Dilutes existing shareholders but raises capital immediately.
3. Issue Tier 1 instruments: Preferred stock or perpetual subordinated debt. Cheaper than common equity but more expensive than retained earnings.
4. Issue Tier 2 debt: Subordinated notes with stated maturity. Cheapest debt-like capital instrument.

Return of capital (dividends, buybacks) happens when capital ratios exceed targets. In 2024, large US banks returned record amounts to shareholders precisely because capital ratios were strong and internal earnings were sufficient to rebuild capital.

Real Example: Capital Allocation at a Large Bank

Consider a $300B asset bank with these metrics:

• Net income: $2.5B annually


• CET1 ratio: 11.5% (target: 10.5%)


• RWA: $180B


• CET1 capital: $20.7B

Earnings of $2.5B grow tangible equity by roughly $2B annually (after loan loss provisions). That's about 10bps of annual CET1 ratio growth (assuming RWA stays flat).

With 100bps excess capital above target, management can allocate that $2B of earnings across:

• Dividend: $1.2B (roughly 5% payout on tangible equity)


• Share buybacks: $600M (opportunistic, when stock is cheap)


• Retained earnings for growth: $200M

This allocation allows the bank to grow the balance sheet (through earnings retention and improved RWA efficiency), return capital to shareholders (through dividends and buybacks), and maintain a buffer above the target ratio.

If the bank grew too aggressively (expanding assets faster than earnings), or if credit losses spiked, or if AOCI deteriorated, the CET1 ratio could fall, forcing management to reduce dividends, cut the buyback, or slow growth.

Capital Structure and Competitive Strategy

Capital structure is strategy. A well-capitalized bank can:

• Underwrite better credits (lower interest rates) and still earn target returns


• Deploy countercyclically (buy distressed assets when others can't)


• Make acquisitions that undercapitalized competitors can't afford


• Take on balance sheet risks that others avoid

A capital-constrained bank must:

• Focus on high-return businesses (trading, wealth management, prime lending)


• Securitize commoditized products (mortgages, auto loans, credit cards)


• Partner with other banks rather than grow organically


• Accept lower market share in capital-intensive segments

This shapes the entire ALM strategy. Mortgage banks live and die by securitization efficiency (it's the only way to manage RWA). Community banks focus on relationship lending where capital efficiency is highest. Large universal banks can afford to hold whole loans because they have capital and can cross-sell.

The Forward-Looking Perspective

ALM managers don't just manage today's capital structure—they project it forward. In interest rate stress scenarios, AOCI deteriorates (unrealized losses on securities increase), which reduces CET1. In credit stress scenarios, loan loss reserves increase and charge-offs reduce retained earnings. In liquidity stress scenarios, funding costs rise, compressing net interest margin and earnings.

Capital forecasting through stress scenarios is the discipline that separates experienced ALM teams from operational ones. You need to know not just where capital is today, but where it will be under a range of plausible futures.