A dealer market is a trading arrangement in which customers buy or sell through dealers that quote prices and trade for their own accounts. The dealer acts as principal: it takes the other side of the customer's trade. For an execution model, the relevant liquidity is the price and quantity the customer can actually obtain from an eligible dealer, rather than every quote visible on a screen.
A sale that adds inventory
Suppose a dealer gives this customer a firm, hypothetical stock quote of USD 99 bid / USD 101 ask per share, for 100 shares on each side. The customer wants to sell 100 shares, the quote remains available, and the whole sale executes. Ignore fees.
The bid is the dealer's buying price. The customer therefore receives USD. The ask is the dealer's selling price; it does not apply to this customer sale.
| Change caused by the trade | Customer | Dealer |
|---|---|---|
| Cash, USD | +9,900 | −9,900 |
| Shares | −100 | +100 |
These entries describe the completed cash-and-securities exchange, not a universal settlement timetable. They do not specify either party's opening balances.
Original synthetic stock trade, with a firm quote accessible to this customer and sufficient size for the stipulated fill. Cash and share entries show changes from before the trade once its obligations are completed. Fees are excluded; the dealer has not resold the acquired shares.
The dealer has supplied immediacy: the seller did not have to wait for an end investor wanting to buy those shares. In return, the dealer has acquired inventory. Its quoted bid-ask spread is USD per share, but the ask has not traded. That spread is not a realised profit on the inventory purchase.
Whose quote can you trade?
Dealer markets can use bilateral conversations, electronic quotes or a request for quote. A customer may compare several dealers. Dealers may also trade with one another to redistribute positions in an interdealer market. The IMF's market-structure explanation distinguishes customer and interdealer relationships and explains why quote visibility and access can differ.
A useful quote comparison checks more than price:
- Eligibility: can this customer trade with this dealer under the relevant credit and trading arrangements?
- Quantity: how much will the dealer execute at that price? Our 100-share quote does not price an arbitrarily larger order.
- Commitment and timing: is the quote firm or indicative, and is it still available when accepted?
- Total cost: what fees or other execution charges apply beyond the quoted price?
A better price from a dealer the customer cannot access is not automatically an executable alternative. Nor should a backtest apply a small-size quote to unlimited volume.
The dealer absorbs a mismatch in time
After buying, the dealer can seek another customer, offset with another dealer or hedge the exposure. None of those future transactions is guaranteed by the initial quote. The price can move while the shares are held: that is inventory risk. A fill can also reveal information that makes the dealer's old quote unattractive, creating adverse selection.
The BIS discussion of market-making economics connects quotes to inventory limits, funding and hedging costs. A dealer approaching its risk limit may change prices or reduce the amount it is willing to trade. If many dealers do so together, available liquidity can shrink precisely when customers want to exit.
Market organisation and legal status answer different questions
“Dealer market” describes how trading is organised. “Dealer” can also be a legal classification of a firm or activity. In U.S. securities law, the SEC's registration guide distinguishes dealing as a business from ordinary own-account trading. A market-structure label alone does not determine a firm's registration obligations; those depend on the jurisdiction, instruments and activities. The guide is older conceptual guidance, not a complete account of current registration requirements.
Likewise, dealer-based trading and over-the-counter trading are closely associated but describe different features. The presence of market makers on an exchange does not make every exchange transaction part of a pure dealer market. Real venues can combine dealer quotes with an order book or auction mechanism.
For the separate question of how a trade's obligations are handled after execution, the Exchanges and OTC Markets lesson compares bilateral and central clearing (membership; public preview).
Sources
- IMF: Financial markets — Exchange or Over the Counter, Randall Dodd — dealer networks, customer/interdealer segments and access differences. Used for market mechanics, not historical venue statistics or a current regulatory survey.
- BIS: The economics of market-making, extract from the March 2015 Quarterly Review, p. 99 — inventory, funding, hedging and liquidity provision.
- SEC: Guide to Broker-Dealer Registration, sections II.A–B — U.S. broker/dealer concepts and the own-account trader distinction; older guidance, with scope qualified above.
- Thierry Foucault, Marco Pagano and Ailsa Röell, Market Liquidity: Theory, Evidence, and Policy, Oxford University Press, 2013, Chapter 1, §1.1, pp. 16–17 and §1.2.2, pp. 24–26 — dealer-market mechanics, quote search, inventory and trade size. All numerical assumptions and the diagram are original.