Learning Outcomes
After reading this article, you will be able to distinguish between key order types, explain the roles of various trading venues, and analyze the cost implications of execution choices. You will learn to identify the main features of market microstructure, assess the impact of order and venue selection on transaction costs, and prepare for CFA exam questions focused on practical execution decisions.
CFA Level 3 Syllabus
For CFA Level 3, you are required to understand the practical and theoretical aspects of market microstructure. In particular, your revision should focus on:
- Recognizing different order types and their characteristics
- Explaining the functions and structure of major trading venues
- Evaluating execution strategies based on order and venue selection
- Estimating explicit and implicit trading costs
Test Your Knowledge
Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.
- What is the primary difference between a limit order and a market order?
- How might a trader use a stop order for downside protection?
- Name one advantage and one disadvantage of executing an order on a dark pool.
- Explain what is meant by “market impact cost.”
Introduction
Market microstructure concerns the mechanics of how financial markets work, particularly the processes, order types, and venues that affect transaction costs and execution quality. At Level 3, you must not only identify order and venue types but also analyze the strategic and cost implications of each choice, as these influence portfolio returns and risk management.
ORDER TYPES
Different order types offer varying trade-offs between immediacy, price certainty, and execution cost. For the CFA exam, you must be able to select an appropriate order based on trading objectives.
Key Term: market order
An order to buy or sell a security at the best available price, executed immediately and fully, but with uncertain price.Key Term: limit order
An order specifying the maximum purchase price or minimum sale price, executed only at the specified price or better, but not guaranteed to execute immediately.Key Term: stop order
An order to buy or sell a security when its price surpasses a specified level, often used to trigger trades in volatile markets or for protection.Key Term: iceberg order
A large order that is split into smaller visible portions to avoid revealing total order size; the undisclosed size remains hidden from the order book.
Order Type Selection
- Market orders prioritize execution over price certainty. Use when liquidity is high and immediate transaction is critical.
- Limit orders control execution price but can result in partial fills or may not execute at all.
- Stop orders are often used for protection; a stop-loss triggers a market sell if the asset falls below a threshold.
- Iceberg orders reduce signaling risk and limit market impact for large trades.
Worked Example 1.1
A manager wishes to buy $5 million of a moderately liquid equity but wants to avoid moving the price. What order type and structure should be used?
Answer:
An iceberg order can be used, placing a limit price with only a small portion displayed and the rest hidden, reducing signaling and market impact.
EXECUTION VENUES
Where an order is sent for execution influences transaction speed, cost, and market impact. You must be able to identify the main venue types and their features.
Key Term: order-driven market
A trading system where buyers and sellers transact directly based on the order book, e.g., most stock exchanges.Key Term: quote-driven market
A market structure in which dealers quote buy/sell prices and stand ready to transact, often used for over-the-counter (OTC) securities.Key Term: crossing network
An alternative trading system that matches buy and sell orders at predetermined times or prices, often without pre-trade transparency.Key Term: dark pool
A private execution venue with no pre-trade transparency, used for large orders to minimize information leakage.
Execution Venue Selection
- Order-driven markets (e.g., NYSE, LSE): offer transparency and depth, but large trades can be visible and may move price.
- Quote-driven markets: provide immediacy and firm two-way prices from dealers; may be costly for less liquid securities.
- Crossing networks/dark pools: help execute large orders with low market impact but may suffer from uncertain fill rates and limited transparency.
Worked Example 1.2
A portfolio manager plans to sell a large block of shares and is concerned about price slippage in the public market. What execution venue is likely to minimize information leakage?
Answer:
A dark pool allows large trades to be executed anonymously with low market impact, though execution is not guaranteed.
MICROSTRUCTURE COSTS
Understand how each execution choice affects both explicit and implicit transaction costs.
Key Term: explicit cost
Direct, out-of-pocket expenses associated with trading, such as commissions, fees, and taxes.Key Term: implicit cost
Indirect costs, including bid-ask spread, market impact, delay, and opportunity costs.Key Term: market impact cost
The price movement caused by executing a trade, measured as the difference between the execution price and an appropriate benchmark.
Main Sources of Cost
- Broker commission and fees (explicit)
- Bid-ask spread (implicit; cost of immediacy)
- Market impact cost (implicit; rising for large or illiquid trades)
- Delay and opportunity cost (implicit; from unfilled or slow orders)
Worked Example 1.3
A trader submits a market order for 40,000 shares in an illiquid stock. The average price received is well above the pre-trade mid-quote. Which cost is most relevant?
Answer:
The primary cost is market impact, as the large order moved the execution price; this is a key implicit cost to analyze.
Exam Warning
A common CFA exam error is to ignore the risk of non-execution or partial fills with limit and iceberg orders, especially in thinly traded securities. Be sure to consider the full cost and execution risk trade-off in all order/venue pairs.
Revision Tip
In CFA scenarios, always link order type and venue choice directly to objectives: Do you need speed, low cost, or stealth? State your reasoning clearly.
Summary
Order types and venue selection are central to execution strategy. Market and limit orders serve distinct objectives—immediacy versus price control. Selecting among execution venues (order-driven, quote-driven, dark pools) affects certainty, impact, and cost. Understanding explicit and implicit costs, including market impact, is critical. CFA exam questions will frequently require justifying choices with reference to these trade-offs.
Key Point Checklist
This article has covered the following key knowledge points:
- Differentiate market, limit, stop, and iceberg orders, and their execution uses
- Identify order-driven, quote-driven, and alternative venues and their trading characteristics
- Analyze how order/venue choice influences explicit and implicit trading costs
- Define and calculate market impact cost; recognize the risk/cost trade-off in order/venue selection
- Justify optimal order type and venue for a stated trading objective
Key Terms and Concepts
- market order
- limit order
- stop order
- iceberg order
- order-driven market
- quote-driven market
- crossing network
- dark pool
- explicit cost
- implicit cost
- market impact cost