Model risk is the risk that a financial model gives wrong answers, is built on weak assumptions, is implemented incorrectly, or is used in the wrong way—and that decisions based on it cause losses, control failures, bad pricing, weak reserves, or regulatory issues. In modern finance, model risk matters anywhere numbers drive action: lending, trading, valuation, capital, expected credit loss, stress testing, fraud monitoring, and strategic planning. Understanding model risk means understanding not only math, but also data quality, governance, controls, validation, and human judgment.

Minority Interest is the portion of a subsidiary that belongs to owners other than the parent company. In modern accounting standards, the preferred term is **Non-controlling Interest (NCI)**, but **Minority Interest** still appears in textbooks, older annual reports, valuation discussions, and interview questions. It matters because a parent may consolidate 100% of a subsidiary’s financial statements even when it owns less than 100%, so the outside owners’ share must be shown separately.

Minority Discount is a valuation adjustment used when an ownership stake does not carry control over a business. In plain terms, a 10% or 20% stake in a private company is often worth less than its simple pro-rata share of the whole company because the holder usually cannot direct strategy, appoint management, force dividends, or sell the company. This concept is central in private company valuation, M&A, tax planning, shareholder disputes, and investment analysis.

In accounting and reporting, **Minority** usually refers to the portion of a subsidiary that is **not owned by the parent company**. In modern standards, the preferred term is **non-controlling interest (NCI)**, but many textbooks, annual reports, valuation models, and interview questions still use **minority interest** or simply **minority**.

MREL, or **Minimum Requirement for own funds and Eligible Liabilities**, is a bank resolution requirement designed to make bank failures more manageable and less reliant on taxpayer support. In simple terms, it tells a bank how much loss-absorbing and recapitalization-capable funding it must maintain so that, if it fails, authorities can stabilize it through resolution. For finance learners, regulators, bank treasurers, credit analysts, and investors, MREL is a core concept in modern banking regulation.

Microprudential Supervision is the part of financial regulation that examines each bank, insurer, or other regulated financial institution individually. Its purpose is straightforward but critical: to make sure each firm is safe, solvent, liquid enough, and well-governed so it can meet its obligations. For students, professionals, investors, and policymakers, understanding microprudential supervision is essential because many financial crises begin with weaknesses inside individual institutions.

Microfinance is the provision of small-scale financial services to people and very small businesses that traditional banking often does not serve well. It includes more than tiny loans: savings, insurance, payments, and credit support can all be part of microfinance. For borrowers, it can improve access and flexibility; for lenders, investors, and policymakers, it is a major tool in financial inclusion—but one that must be designed carefully to avoid over-indebtedness and abuse.

MiFIR, short for the Markets in Financial Instruments Regulation, is a core part of the European rulebook for how financial markets operate. It governs areas such as trade transparency, transaction reporting, trading obligations, and market data, making it highly relevant for banks, brokers, asset managers, trading venues, and regulators. If you want to understand how EU market structure works in practice, MiFIR is one of the first regulations to study.

MiFID II is one of the most important financial market regulations in modern Europe. It reshaped how investment firms classify clients, disclose costs, route orders, monitor trading, report transactions, govern products, and control conflicts of interest. Even if you do not work in the European Union, MiFID II matters because its standards influence global brokerage, asset management, trading technology, and compliance practice.

MiCA, short for the EU Markets in Crypto-Assets Regulation, is one of the most important crypto rulebooks in modern finance. It gives the European Union a unified framework for crypto-asset issuance, stablecoins, exchanges, custody providers, and market conduct. If you work with tokens, crypto platforms, fintech compliance, or cross-border digital finance, understanding MiCA is now essential.

Mezzanine debt is a middle-layer financing tool that sits between senior debt and equity in a company’s capital structure. It is used when a borrower needs more capital than senior lenders will provide, but owners do not want to issue too much new equity. Because it takes more risk than senior debt, mezzanine debt usually demands a higher return through interest, fees, and sometimes equity upside.

In accounting and reporting, a **method** is the defined way a task is performed: how revenue is recognized, inventory is costed, an asset is depreciated, an investment is accounted for, or audit evidence is gathered. The word sounds generic, but methods directly affect reported profit, asset values, ratios, disclosures, and comparability. If you understand the method, you usually understand how the numbers were built.

Merger reserve is an equity reserve that can arise when a company acquires another company by issuing shares, especially where local company law permits merger relief or merger accounting. It matters because the amount may be recorded differently from share premium or retained earnings, which affects financial reporting, legal capital, distributability, and deal analysis. If you read statutory accounts, audit files, or post-merger equity notes, understanding merger reserve helps you avoid serious interpretation errors.

A merger is one of the most important events a business can go through because it changes ownership, control, financial reporting, and strategy at the same time. In simple terms, a merger combines two separate businesses into one economic unit, but the legal structure and accounting treatment are not always the same. In modern finance, accounting, and reporting, many deals called mergers are accounted for as business combinations, so understanding both the business meaning and the reporting meaning is essential.

Merchant Discount Rate (MDR) is the fee a merchant pays to accept card payments and, in some markets, certain other digital payment instruments. It affects sales margin, cash settlement, payment pricing, and even public policy on digital payments. If you understand MDR well, you can read payment statements more accurately, negotiate better acquiring terms, and evaluate payment businesses with much greater clarity.

MDR stands for **Merchant Discount Rate**, a payment-processing fee that merchants pay when they accept cards and, in some markets, certain digital payment instruments. It directly affects business margins, pricing decisions, payment-method strategy, and even public policy on digital payments. If you understand MDR well, you understand a major part of how modern payment systems actually get funded.

A **merchant bank** is a financial institution that helps businesses raise capital, manage major transactions, and obtain strategic financial advice. The term is old, but it still matters because it sits at the intersection of banking, capital markets, corporate finance, and regulation. In modern practice, a merchant bank may advise on public issues, private placements, mergers and acquisitions, restructuring, and, in some jurisdictions, principal investment.

Merchandise is a simple word with major financial consequences. In finance and accounting, it usually means goods held for resale, but it also matters in lending, business analysis, inventory management, and international trade data. If you understand merchandise well, you understand how many businesses convert cash into goods and goods back into cash at a profit.

A **Medium-term Window** is a central-bank liquidity channel that gives eligible banks funding for more than just overnight or very short periods, usually against collateral. It matters because it helps banks manage funding gaps, supports monetary policy transmission, and can stabilize markets when short-term funding becomes unreliable. In practice, the exact name and design differ by central bank, so the term is often best understood as a policy-instrument category rather than one globally uniform legal label.

A **Medium-term Swap Line** is a central-bank liquidity arrangement that allows one central bank to obtain foreign currency from another for a pre-agreed medium tenor, typically to support banks, payment systems, trade finance, or market stability. In plain language, it is a back-up funding bridge between monetary authorities when foreign-currency liquidity becomes scarce. It matters because cross-border banking systems can face funding stress quickly, and medium-term liquidity support can prevent a short-term squeeze from becoming a broader financial crisis.

A Medium-term Repo Facility is a central-bank liquidity tool that gives eligible financial institutions funding for more than just overnight or very short periods, usually against approved collateral. In simple terms, banks temporarily hand over securities, receive cash, and agree to buy those securities back later at a pre-agreed price. This matters because it helps central banks manage liquidity, steady financial markets, and improve monetary policy transmission beyond the shortest end of the money market.

A Medium-term Refinancing Operation is a central-bank liquidity tool through which eligible banks obtain funds for a period longer than overnight or weekly borrowing, but shorter than long-horizon structural or emergency facilities. In plain terms, it gives banks a more stable funding bridge for weeks or months, usually against high-quality collateral. Understanding this instrument helps explain how central banks manage liquidity, guide interest rates, and support credit flow in the economy.

A Medium-term Liquidity Line is a central-bank liquidity tool that gives eligible financial institutions funding for longer than overnight or very short-term operations, typically against collateral. In plain language, it is a bridge source of cash for banks when short-term market funding is unreliable, expensive, or too risky to roll over repeatedly. Although the exact label is not used uniformly across all jurisdictions, the concept is important in monetary policy, liquidity management, banking stability, and market analysis.

A Medium-term Liquidity Facility is a central-bank tool used to provide banks with funding for longer than overnight or very short-term operations, usually against eligible collateral. It matters because it helps stabilize the banking system, guide interest rates, and support the flow of credit to households and businesses. In practical discussion, the exact design varies by country, and some jurisdictions use closely related labels such as a Medium-term Lending Facility.

A Medium-term Funding Scheme is a central-bank liquidity tool that gives eligible financial institutions funding for longer than overnight or very short-term operations, usually against collateral and under defined policy conditions. It matters because it can stabilize bank funding, improve credit transmission, and reduce the risk that short-term market stress turns into a lending squeeze for the real economy. In plain terms, it is a way for a central bank to give banks breathing room for months or years rather than days.

A **Medium-term Credit Facility** is a central-bank liquidity tool that gives eligible financial institutions access to funding for a period longer than overnight, usually against acceptable collateral. It helps banks bridge temporary funding gaps, supports smoother transmission of monetary policy, and can reduce the need for forced asset sales during stress. For students, treasury professionals, investors, and policy watchers, understanding this facility is essential for reading how modern liquidity systems actually work.

The **Medium-term Collateral Framework** is a central-banking concept that explains which assets banks can pledge when they borrow liquidity from a central bank for a period longer than very short-term overnight funding. It matters because access to central bank liquidity depends not just on the borrowing facility itself, but on the collateral rules behind it. For anyone studying monetary policy, bank funding, or financial stability, this framework is a practical bridge between policy design and real-world liquidity management.

A **Medium-term Asset Purchase Programme** is a central-bank policy tool under which the central bank buys eligible securities over a multi-month or multi-year horizon to inject liquidity, influence medium- to long-term interest rates, and support monetary policy transmission. In plain terms, it is a structured bond-buying or asset-buying plan designed to make financial conditions easier when ordinary rate cuts are not enough or when market functioning is impaired. Understanding this term helps readers interpret bond yields, bank liquidity, policy statements, and balance-sheet changes across modern monetary systems.

Measurement in accounting is the process of deciding the monetary amount at which assets, liabilities, income, and expenses appear in financial statements. It sounds technical, but it directly affects reported profit, net worth, leverage, tax timing, and investor confidence. If you understand measurement, you can better read accounts, prepare reports, challenge assumptions, and avoid common reporting mistakes.

Maturity transformation is one of the central functions of banking: institutions take funds that can be withdrawn or rolled over soon and use them to finance loans or investments that last much longer. This supports mortgages, business lending, and economic growth, but it also creates liquidity risk, rollover risk, and interest-rate risk. If you want to understand how banks earn money, why bank runs happen, and why regulators care so much about liquidity, you need to understand maturity transformation.