A "long margin purchase" is a specific type of securities transaction. "Long" indicates the investor is buying the security with the expectation that its price will increase. "Margin" signifies that the investor is borrowing a portion of the purchase price from their broker. "At market" refers to a market order, which is executed immediately at the best available price. Therefore, the investor is buying common shares at the current price using a combination of their own and borrowed funds.

A. Buying shares using entirely one's own funds is known as a cash purchase, not a margin purchase.

B. Placing an order to buy only when a price drops to a specific level describes a limit order, not a market order.

D. Borrowing shares to sell them is the definition of a short sale, which is the opposite of a long purchase.

1. Bodie, Z., Kane, A., & Marcus, A. J. (2021). Investments (12th ed.). McGraw-Hill Education. Chapter 3, "How Securities Are Traded," Section 3.6 "Margin," pp. 78-81.

2. Canadian Securities Institute. (2023). Investment Funds in Canada Course Textbook. Chapter 10, "Working with the Client," Section on Margin Accounts, pp. 250-252.

3. Teweles, R. J., & Bradley, E. S. (1998). The Stock Market (7th ed.). John Wiley & Sons. Chapter 10, "Margin," pp. 215-218.