The Deutscher Aktienindex, or DAX, is Germany’s best known stock market index and tracks the performance of the 30 largest German companies in terms of market capitalisation (stock market value) and exchange turnover. It thus allows a quick assessment of current market conditions and serves as a benchmark for the German stock market. The DAX started from a base value of 1,000 index points on 31 December 1987 and has been published by Deutsche Börse AG since 1 July 1988. If the DAX stands at 10,000 index points, for instance, the value of the shares contained in it has increased tenfold since then. The DAX as communicated in the media is a performance index, which includes dividend payments. The DAX is additionally quoted as a pure price index, i.e. without counting dividend payments. To be listed in the DAX, companies must meet various criteria. They are required to follow very strict transparency rules and meet certain conditions in terms of market capitalisation and exchange turnover. Deutsche Börse AG decides on the composition of the DAX.

A debit card – a plastic card the same size as a credit card – is a cashless payment instrument which is issued by financial institutions to their customers. It is also known as girocard. Details of the debit card holder's account are stored on the debit card. To effect a payment, these details are read from the card via an electronic point-of-sale terminal and a debit to the debit card holder's account for the amount of the payment is activated. However, the payer must first authorise the payment by entering a secret number in the point-of-sale terminal. In a variant of this procedure – the electronic direct debit system – debit card holders authorise a debit to their account by signing the sales voucher. In contrast to a credit card payment, when using a debit card the payer's account is debited rapidly.

The debt brake is a budgetary rule laid down in the German constitution since 2009, which since 2011 has set out mandatory requirements for the Federal Government and the states to gradually reduce the budget deficit. From 2016, the Federal Government's annual structural (i.e. not cyclical) deficit must be no more than 0.35% of gross domestic product. As of 2020, net borrowing by the federal states will no longer be permitted. Exceptions to the ban on new borrowing are permitted under certain conditions, however.

Debt capital is that part of an enterprise's total assets which is not provided by the company's owners (equity providers). It is the collective term used to refer to all the liabilities and provisions listed on a company's balance sheet. In this context, liabilities include inter aliabank loans, debt securities issued by the company in question, loans from suppliers and any advance payments received. The debt investor has no stake in the company and serves as the creditor who has a right to repayment (redemption) of his capital and, where appropriate, due interest.

The holder of a debt security (creditor) provides the issuer (borrower) with a specific amount for a certain period. The issuer undertakes to pay this amount back to the holder of the debt security upon maturity. The issuer also pays the creditor interest under the terms of the bond. The issuer uses the debt security to raise funds, while it provides the creditor with an interest-bearing investment. Debt securities are issued by public sector bodies (public sector bonds), banks (bank debt securities, Pfandbriefe) and industrial enterprises (corporate bonds). Should the issuer default, creditors’ claims can only be met by the issuer’s estate. The opposite is the case for covered bonds: if the issuer defaults, creditors receive payments from a pool of securities that does not form part of the issuer’s bankrupt’s estate.

A deficit, or negative budget balance, occurs when spending exceeds revenue. The government budget is said to be in deficit when the state spends more money than it collects in taxes and levies.

Deficit spending refers to a situation where government institutions step up their expenditure during a recession by taking out additional loans. Deficit spending aims to stimulate demand in the economy and thus boost employment, for instance. Governments should ideally reduce the new debt incurred through deficit spending by running a surplus during the subsequent boom.

Deflation refers to a general, sustained decline in the price level. In a deflationary climate, there is the risk of a self-perpetuating downward spiral: if consumers expect prices to continue falling and therefore put their consumption spending on hold, the decline in demand can lead enterpises to cut back production and lower prices even more. Falling prices also increase the real equivalent of outstanding debts and the real interest rates. This tends to also lower demand, especially demand for capital goods. The monetary policy measures that can be used to combat deflation are restricted, as nominal interest rates cannot be reduced to below zero per cent.

The nominal value sequence of a series of coins and banknotes. The denominations of euro coins are 1, 2, 5, 10, 20 and 50 euro cents as well as 1 and 2 euro, and the denominations of euro banknotes are 5, 10, 20, 50, 100, 200 and 500 euro.

Deposit is the technical banking term for a balance held by a customer in his/her bank account. There are several types of deposits. Customers can access sight deposits at any time by withdrawing or transferring cash, for example. Savings deposits usually have no limitation in time. The depositor can reclaim the deposit from the bank after a specific period of notice has elapsed.  Interest rates for savings deposits are generally variable, changing with general interest rate movements. Time deposits are deposits held for a fixed period, eg three months or one year. Interest on time deposits is usually fixed in advance for the entire period when the contract is concluded. Banks use savings and time deposits to finance their medium and long-term lending business.

The deposit facility is a monetary policy instrument of the Eurosystem; it provides banks with the ongoing option of making overnight deposits at the national central banks, which are remunerated at a pre-specified interest rate. The interest rate for the deposit facility constitutes the lower limit for the overnight money market rate and is thus one of the Eurosystem's key interest rates.

Deposit money is money held with a bank which a bank customer can access daily. It is only available to the bank "on sight", hence the term "sight deposit". Although deposit money is not legal tender, it is generally accepted as a means of payment. Deposit money can be used to make payments via cashless payment instruments such as credit transfers, direct debits or cheques. It can be converted into cash at any time.

Deposit protection is a scheme designed to protect bank customers from losing their deposits if their bank becomes insolvent. The statutory deposit protection scheme covers deposits in current accounts, savings accounts, notice accounts and time deposit accounts up to a value of €100,000 per customer. The banking industry in Germany also offers voluntary guarantee schemes for additional protection.

Deregulation refers to the removal or reduction of statutory regulations that restrict the functioning of the goods, labour and finance markets. The aim of a more liberal framework (eg greater competition) is to increase incentives and broaden the scope for action.

Derivatives in banking language are financial instruments whose prices depend on the price movements in a reference variable, known as the underlying. Underlying assets may be shares, equity indices, government bonds, currencies, interest rates, commodities like wheat and gold, or also swaps. Derivative financial instruments may be unconditional forward transactions or they may be options. They are traded either on futures and options exchanges on standardised terms, or over-the-counter (OTC) on freely negotiated terms. Changes in the price of the underlying lead in certain situations to considerably stronger price changes in the derivative. Derivatives can be used to hedge against financial risks (hedging), to speculate on price changes (trading) or to take advantage of price differences between markets (arbitrage).

The Deutsche Bundesbank is the central bank of the Federal Republic of Germany and has, since monetary union was established, been part of the European System of Central Banks (ESCB) and the Eurosystem. The Bundesbank's president is a member of the ECB Governing Council. The Bundesbank therefore plays a role in fulfilling the primary objective of the Eurosystem, namely to maintain price stability. In addition, the Bundesbank implements monetary policy in Germany, is involved in banking supervision, works towards a stable financial and monetary system, ensures that cashless payments can be executed smoothly, manages Germany's foreign reserves and puts cash into circulation. The Bundesbank’s Central Office is in Frankfurt am Main.

The Deutsche Mark (abbreviated DM, commonly referred to as D-Mark) was the currency of the Federal Republic of Germany from 20 June 1948 to the end of 2001. The Deutsche Mark replaced the Reichsmark in 1948. Through the reunification of Germany, it was also adopted as the official currency in eastern Germany on 1 July 1990. Within the framework of Economic and Monetary Union, the euro eventually replaced the Deutsche Mark as legal tender on 1 January 2002, after it had already been introduced as book money on 1 January 1999. The exchange rate was fixed at €1 = DM1.95583. The Deutsche Mark was one of the most stable currencies of its time, gaining the status of the second most important reserve currency in the world, after the US dollar. It was even employed as official currency in other countries.

Banknotes and coins denominated in Deutsche Mark can be exchanged at the Bundesbank’s branches indefinitely and free of charge.

A direct bank is a bank that does not operate any branches or subsidiaries, and which is only accessible over the telephone, by letter or via the internet for banking business.  Direct banks therefore offer cost advantages, which they can pass on to customers in the form of attractive terms and conditions.

A direct debit is a cashless payment instrument that allows the payee to debit an amount on the payer's account via a bank. Direct debits are useful for irregular or variable payments: they save both time and effort and help to avoid forgetting a payment. Unlike credit transfers, direct debits are initiated by the payee, who has obtained the payer's consent in advance. If the payer does not agree to his or her account being debited, he or she can revoke the direct debit within certain deadlines.

A SEPA direct debit mandate is the legal basis for collecting SEPA direct debits. A mandate comprises both the payer's approval for the payee to collect the payment via SEPA direct debit and the instruction to the payer's payment service provider to effect the payment.

Direct investment is cross-border investment with the aim of establishing subsidiaries in a different country or taking a major capital interest in enterprises abroad such that influence can be exercised over their business operations. Direct investment forms part of the financial accounts; it also includes all transactions between the affiliated enterprises, ie corporate loans. Enterprises make direct investments in other countries in order to tap new sales markets or maintain existing ones, circumvent trade barriers or take advantage of the cost benefits of producing goods abroad. It is not uncommon for host countries to benefit from the transfer of technology associated with direct investment.

Exchange rates between two currencies can be quoted indirectly or directly. Direct quotation states how much one unit of foreign currency costs  in domestic currency units (eg $1 = €0.73), whereas indirect quotation states how many units of foreign currency you would receive for one unit of domestic currency (eg €1 = $1.37). In foreign exchange trading, the international convention is to quote the euro against all other currencies using the indirect quotation method.

Discount business is the purchase of trade bills by a bank or a central bank, which deducts interest at the discount rate. In the past, discount business constituted the core business of a central bank, which used the short-term bills it purchased to cover some of the bank notes it issued. As a result of the creation of a single list of collateral for monetary policy transactions in the euro area, the purchase of trade bills was discontinued.

Disintermediation refers to the process of increasing lending via the capital market, circumventing the commercial banks, which were previously the most important financial intermediaries. As monetary policy measures affect commercial banks first and foremost, disintermediation alters and disrupts the monetary policy transmission mechanism.

Characterised by its decentralised data storage, distributed ledger technology (DLT) is the technology on which blockchain is based. It is considered to have a promising future, as the decentralised storage of data offers certain advantages over centralised storage. First, it offers protection against system failure, as individual systems which have crashed can always be replaced by other systems. Second, it rules out the possibility of a centralised computer being manipulated.

A dividend is the proportion of a public limited company's distributed profits that is allocated to a single share. The dividend yield is the dividend divided by the current share price multiplied by 100. It specifies the return on invested capital per share and is expressed as a percentage.