Which of the following best describes a cross between the auction and dealer market?

The correct choice is ECNs, which stands for Electronic Communication Networks. These platforms serve to facilitate trading by connecting buyers and sellers directly, similar to the auction market where the price is determined through bids. However, ECNs also function like dealer markets, as they allow for automatic matching of orders and provide liquidity by aggregating quotes from multiple participants.

In an ECN, the trading process involves both aspects of price negotiation seen in auction markets and the provision of quotes and liquidity found in dealer markets. Thus, ECNs effectively blend the features of both types of markets, allowing for greater efficiency, lower transaction costs, and the ability to trade outside of standard market hours.

The other options do not encapsulate this blend as effectively. A broker market primarily acts as an intermediary, facilitating trades but not directly engaging in price setting or liquidity provision. A direct search market relies on buyers and sellers finding each other without intermediary assistance, which does not combine the auction and dealer functionalities. The primary market is specifically focused on the issuance of new securities rather than the trading and pricing mechanisms that characterize secondary markets like auction and dealer markets.