The traditional asset-management approach to banking is based on the assumption that a bank’s liabilities are both relatively stable and unmarketable. Historically, each bank relied on a market for its deposit IOUs that was influenced by the bank’s location, meaning that any changes in the extent of the market (and hence in the total amount of resources available to fund the bank’s loans and investments) were beyond a bank’s immediate control. In the 1960s and ’70s, however, this assumption was abandoned. The change occurred first in the United States, where rising interest rates, together with regulations limiting the interest rates banks could pay, made it increasingly difficult for banks to attract and maintain deposits. Consequently, bankers devised a variety of alternative devices for acquiring funds, including repurchase agreements, which involve the selling of securities on the condition that buyers agree to repurchase them at a stated date in the future, and negotiable certificates of deposit (CDs), which can be traded in a secondary market. Having discovered new ways to acquire funds, banks no longer waited for funds to arrive through the normal course of business. The new approaches enabled banks to manage the liability as well as the asset side of their balance sheets. Such active purchasing and selling of funds by banks, known as liability management, allows bankers to exploit profitable lending opportunities without being limited by a lack of funds for loans. Once liability management became an established practice in the United States, it quickly spread to Canada and the United Kingdom and eventually to banking systems worldwide.

A more recent approach to bank management synthesizes the asset- and liability-management approaches. Known as risk management, this approach essentially treats banks as bundles of risks; the primary challenge for bank managers is to establish acceptable degrees of risk exposure. This means bank managers must calculate a reasonably reliable measure of their bank’s overall exposure to various risks and then adjust the bank’s portfolio to achieve both an acceptable overall risk level and the greatest shareholder value consistent with that level.

Contemporary banks face a wide variety of risks. In addition to liquidity risk, they include credit risk (the risk that borrowers will fail to repay their loans on schedule), interest-rate risk (the risk that market interest rates will rise relative to rates being earned on outstanding long-term loans), market risk (the risk of suffering losses in connection with asset and liability trading), foreign-exchange risk (the risk of a foreign currency in which loans have been made being devalued during the loans’ duration), and sovereign risk (the risk that a government will default on its debt). The risk-management approach differs from earlier approaches to bank management in advocating not simply the avoidance of risk but the optimization of it—a strategy that is accomplished by mixing and matching various risky assets, including investment instruments traditionally shunned by bankers, such as forward and futures contracts, options, and other so-called “derivatives” (securities whose value derives from that of other, underlying assets). Despite the level of risk associated with them, derivatives can be used to hedge losses on other risky assets. For example, a bank manager may wish to protect his bank against a possible fall in the value of its bond holdings if interest rates rise during the following three months. In this case he can purchase a three-month forward contract—that is, by selling the bonds for delivery in three months’ time—or, alternatively, take a short position—a promise to sell a particular amount at a specific price—in bond futures. If interest rates do happen to rise during that period, profits from the forward contract or short futures position should completely offset the loss in the capital value of the bonds. The goal is not to change the expected portfolio return but rather to reduce the variance of the return, thereby keeping the actual return closer to its expected value.

The risk-management approach relies upon techniques, such as value at risk, or VAR (which measures the maximum likely loss on a portfolio during the next 100 days or so), that quantify overall risk exposure. One shortcoming of such risk measures is that they generally fail to consider high-impact low-probability events, such as the bombing of the Central Bank of Sri Lanka in 1996 or the September 11 attacks in 2001. Another is that poorly selected or poorly monitored hedge investments can become significant liabilities in themselves, as occurred when the U.S. bank JPMorgan Chase lost more than $3 billion in trades of credit-based derivatives in 2012. For these reasons, traditional bank management tools, including reliance upon bank capital, must continue to play a role in risk management.

Because even the best risk-management techniques cannot guarantee against losses, banks cannot rely on deposits alone to fund their investments. Funding also comes from share owners’ equity, which means that bank managers must concern themselves with the value of the bank’s equity capital as well as the composition of the bank’s assets and liabilities. A bank’s shareholders, however, are residual claimants, meaning that they may share in the bank’s profits but are also the first to bear any losses stemming from bad loans or failed investments. When the value of a bank’s assets declines, shareholders bear the loss, at least up to the point at which their shares become worthless, while depositors stand to suffer only if losses mount high enough to exhaust the bank’s equity, rendering the bank insolvent. In that case, the bank may be closed and its assets liquidated, with depositors (and, after them, if anything remains, other creditors) receiving prorated shares of the proceeds. Where bank deposits are not insured or otherwise guaranteed by government authorities, bank equity capital serves as depositors’ principal source of security against bank losses.

Deposit guarantees, whether explicit (as with deposit insurance) or implicit (as when government authorities are expected to bail out failing banks), can have the unintended consequence of reducing a bank’s equity capital, for which such guarantees are a substitute. Regulators have in turn attempted to compensate for this effect by regulating bank capital. For example, the first (1988) and second (2004) Basel Accords (Basel I and Basel II), which were implemented within the European Union and, to a limited extent, in the United States, established minimum capital requirements for different banks based on formulas that attempted to account for the risks to which each is exposed. Thus, Basel I established an 8 percent capital-to-asset ratio target, with bank assets weighted according to the risk of loss; weights ranged from zero (for top-rated government securities) to one (for some corporate bonds). Following the global financial crisis of 2008–09, a new agreement, known as Basel III (2010), increased capital requirements and imposed other safeguards in rules that would be implemented gradually through early 2019.