A transaction in which a large block of securities is traded between two investors will most likely occur in a(n):

In a broker-driven market, transactions involving large blocks of securities are typically facilitated by brokers who act as intermediaries between buyers and sellers. These brokers have the expertise and relationships necessary to handle substantial trades that might be difficult to execute in other types of markets without significantly impacting the price of the securities.

Such large transactions can often distort the supply and demand dynamics in an order-driven or quote-driven market, which may struggle to absorb large orders without changing the market price significantly. In a broker-driven market, however, brokers can negotiate terms privately or coordinate trades between multiple parties to attain favorable pricing, thereby minimizing market disruption.

This structure is particularly advantageous for institutional investors who wish to maintain discretion and ensure that their large trades do not negatively affect the market. The ability to conduct trades in a more controlled and less transparent environment makes broker-driven markets suitable for these kinds of substantial transactions.