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Regulation T (Reg T): Definition of Requirement and Example


Regulation T (Reg T) is a directive issued by the Federal Reserve Board of the United States which establishes initial margin requirements and payment rules in the securities market. Its primary goal is to control the amount of credit that brokerage firms and dealers may extend to customers for the purchase of securities, in an attempt to manage systemic risk. For example, under Reg T, an investor may be required to deposit at least 50% of the purchase price of securities when buying on margin.


Phonetics of the keyword: Regulation T (Reg T): Definition of Requirement and Example:Regulation T: /ˌrɛgjʊˈleɪʃən/ /ti:/Definition: /ˌdɛfɪˈnɪʃən/of: /ʌv/Requirement: /rɪˈkwaɪərmənt/and: /ænd/Example: /ɪgˈzɑ:mpəl/

Key Takeaways

Regulation T, or Reg T, is an area of finance that instantly grabs the attention of investors, especially those who are engaged in purchasing securities. Here are three crucial takeaways of Regulation T:

  1. Definition and Purpose: Instituted by the Federal Reserve Board, Regulation T governs the rules of cash accounts and the amount of credit that can be issued by brokers or dealers to investors for purchasing securities. The main intent behind Reg T is to safeguard financial markets against excessive speculative activity that could lead to instabilities of significant magnitude.
  2. Initial Margin Requirement: Reg T directly affects margin trading by establishing the initial margin requirement at 50%. This means that investors must front a deposit of 50% of the total cost of the securities they wish to purchase on margin. The remaining 50% can be funded by the broker or dealer, effectively being loaned to the investor.
  3. Implications and Examples: Violations of Regulation T can lead to severe penalties, including restrictions on future margin trading. For instance, if an investor purchased $50,000 worth of stock on margin under Regulation T, he or she would be required to deposit $25,000 in cash or eligible securities. Failure to meet this requirement could lead to penalties or restrictions from the broker or the Federal Reserve.


Regulation T (Reg T) is a crucial financial guideline set forth by the Federal Reserve Board in the United States, governing the amount of credit brokerage firms and dealers may extend to customers for buying securities. The importance of Reg T lies in its aim to control the risk of investing in the volatile stock market by setting a limit on the use of margin accounts – essentially limiting the amount one can borrow for securities investments with a requirement of at least 50% down payment. This not only helps ensure the stability of the financial system by curbing excessive speculative behaviour, but also protects individual investors from taking on too much debt and potentially incurring severe losses. Hence, Reg T plays an essential role in maintaining the balance and stability of the financial markets and safeguarding individual investors’ interests.


Regulation T, often referred to as Reg T, is a directive issued by the Federal Reserve Bank of the United States that stipulates the amount of credit that can be provided to customers by brokers, dealers, banking institutions, etc., for the purchase of securities. The primary purpose of Regulation T is to control the potential risks associated with providing credit for investment related transactions. It ensures that the finance market maintains a certain level of stability and prevent undue speculative activities by traders. Reg T introduces a ceiling to the amount of credit that can be extended, effectively defining the margin requirements for these transactions.For instance, according to the current stipulation of Reg T, only up to 50% of the purchase price of a security can be borrowed. If a trader wants to buy $10,000 worth of securities, they need to fund at least $5,000 using their own money and can borrow the remaining half as the margin loan. Therefore, Regulation T acts as a throttle on the amount of trading activity that can be fueled by credit. This is essentially a safeguard to reduce the level of speculation in the securities market and to mitigate the systemic risks associated with it.


Regulation T, also known as Reg T, is a federal legislation issued by the U.S. Federal Reserve Board. It mandates customer cash accounts and margin accounts from broker-dealers and regulates the amount of credit that brokerage firms and dealers could extend to customers for buying securities. Here are three real-world examples of Reg T:1. Brokerage Account: Suppose an investor opens a margin account with a broker-dealer. If the investor decides to purchase securities worth $20,000, according to Reg T, they must deposit at least 50% of this value, i.e., $10,000, into their account. The brokerage can then lend the investor the remaining amount. 2. Stock Purchases: John is a day trader who wants to buy $8,000 worth of a particular company’s shares, but he only has $3,000. With a margin account, he can borrow the rest from his broker. However, under Reg T, he would initially need to provide at least 50% of the purchase value. In this case, that would be $4,000. John would thus be unable to make the purchase using the money currently in his account.3. Short Selling: If Sally wants to short sell a stock worth $10,000, according to Regulation T, she would need to deposit at least 50% of the value of the shorts in her account with her broker. This equates to $5,000. She can then borrow the remaining from her brokers to make the short sale.Remember that the rules under Regulation T don’t just apply to cash accounts, but also to other transactions such as short sales and options.

Frequently Asked Questions(FAQ)

What is Regulation T (Reg T)?

Regulation T (Reg T) is a series of regulations set forth by the Federal Reserve Board. It governs customer cash accounts and the amount of credit that brokerage firms and dealers can extend to customers to purchase securities.

Who issued Regulation T?

Regulation T was issued by the Federal Reserve Board in the United States.

What is the significance of Regulation T?

It’s important as it sets limits on the amount of credit that customers can obtain from brokerage firms in margin transactions. This helps to control the volatility of the market and prevents customers from over-leveraging themselves.

How does Regulation T affect margin transactions?

According to Regulation T, brokers can lend their customers a maximum of 50% of the purchase price of marginable securities. The customer must deposit the remaining balance, which constitutes the customer’s equity in the margin account.

Can the Federal Reserve change the requirements of Regulation T?

Yes, the Federal Reserve Board has the authority to change the requirements of Regulation T. Changes occur when the board deems it necessary to safeguard economic stability or address increased market risk.

Can you provide an example of Regulation T in action?

Certainly. Suppose an investor wants to buy $10,000 worth of a marginable stock. Under Regulation T, they would need to provide a minimum of $5,000 (50% of the purchase). The broker could lend the remaining amount to the investor.

How does Regulation T protect investors?

Regulation T protects investors by preventing them from over-leveraging themselves. It also stabilizes the financial system by limiting the amount of credit brokers and dealers can extend, reducing potential liability in a market downturn.

Are all securities subject to Regulation T?

Not all securities are subject to Regulation T requirements. Some securities, such as options, are not considered marginable. You should refer to the regulations or consult with a broker for specifics.

Related Finance Terms

  • Initial Margin Requirement: This refers to the percentage of the total market value of securities that an investor must pay for with his/her own cash, or capital, at the time of purchase. Under Regulation T, this is usually set at 50%.
  • Maintenance Margin Requirement: This is the minimum amount of equity that an investor must maintain in their margin account after the purchase has been made. Regulation T does not impose a maintenance margin requirement; this is instead regulated by the self-regulatory organizations.
  • Margin Call: If a margin account falls below the maintenance margin requirement, the broker can issue a margin call, demanding that the investor deposit more funds or securities into the account to bring it up to the minimum value.
  • Federal Reserve Board (FRB): Regulation T is an extension of the Federal Reserve Board, responsible for governing the provisions of credit by brokers, dealers, and members of national securities exchanges to their customers.
  • Credit Extension: Refers to the loan given to an investor to purchase securities, governed by Regulation T. Typically, the credit cannot exceed 50% of the cost of purchasing the security, or the “initial margin requirement”.

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