The outline names exactly four kinds of market, and stops there on purpose. The primary market is where a security is issued for the first time. The issuer gets the proceeds directly. Securities Act sections 7 and 10 govern that stage. The secondary market is existing securities trading among investors afterward, on an exchange, over the counter, or electronically. Exchange Act sections 12 and 15 govern it instead. The issuer is not a party to any of these trades, and gets none of the proceeds. The third market is a narrower case of the second: a listed security, traded over the counter instead of on its own exchange. Same security, same listing, a different venue for this one trade. The fourth market removes a participant entirely: two large institutions trading directly with each other, with no broker-dealer between them. It is the narrowest of the four, and the one candidates most often forget exists at all.

Two terms sound like they belong on this list and do not. A secondary distribution is not an ordinary secondary-market trade. FINRA Rule 2269 uses that exact phrase for a large existing holder selling registered shares in bulk, at a fixed price, through an underwriter. That behaves like an offering, priced like the primary market, not a routine trade on an exchange. The rule requires written notice of that interest at or before completion of the transaction. The deadline runs to completion, not a fixed number of days beforehand.

A dark pool is the other trap. It is a kind of alternative trading system, an ATS, whose orders are not shown publicly before they execute. It is a venue inside the secondary market. It is not a fifth market type; the outline's own list has no fifth line for it, and an answer choice that invents one is always wrong on this exam by construction.

The habit worth building here: read a fact pattern and ask first who receives the proceeds (a primary-market signal), then whether a broker-dealer stands between the two sides (present rules out the fourth market), then whether the security is listed and the trade happens off its own exchange (the third market's own specific shape).