Reading 29 Execution of Portfolio Decisions Flashcards
Buy-side tradres, what a portfolio manager has to know/do about executung trading decisions?
Buy-side traders are the professional traders employed by investment managers or institutional investors who place the trades that execute the decisions of portfolio managers. The job of such traders is to execute the desired trades quickly, without error, and at favorable prices.
Execution is the final, critical step in the interlinked investment process: The portfolio decision is not complete until securities are bought or sold.
A portfolio manager is not a professional trader. However, a portfolio manager does need to:
- communicate effectively with professional traders;
- evaluate the quality of the execution services being provided for the firm’s clients; and
- take responsibility for achieving best execution on behalf of clients in his or her role as a fiduciary.
To accomplish those goals, the portfolio manager needs a grounding in:
- the market institutions within which traders work, including the different types of trading venues to which traders may direct orders;
- the measurement of trading costs; and
- the tactics and strategies available to the firm’s traders and the counterparties with whom they deal, including important innovations in trading technology.
Market microstructure
Market microstructure - the market structures and processes that affect how the manager’s interest in buying or selling an asset is translated into executed trades (represented by trade prices and volumes).
Main order types
Market orders and limit orders are the two major types of orders that traders use and that portfolio managers need to understand.
- A market order is an instruction to execute an order promptly in the public markets at the best price available.
* A market order emphasizes immediacy of execution*. However, a market order usually bears some degree of price uncertainty (uncertainty about the price at which the order will execute). In today’s markets, most market orders are effectively automated from the point of origin straight through to reporting and clearing. - A limit order is an instruction to trade at the best price available but only if the price is at least as good as the limit price specified in the order. For buy orders, the trade price must not exceed the limit price, while for sell orders, the trade price must be at least as high as the limit price. An instruction always accompanies a limit order specifying when it will expire.
By specifying the least favorable price at which an order can execute, a limit order emphasizes price. However, limit orders can execute only when the market price reaches the limit price specified by the limit order. The timing of the execution, or even whether the execution happens at all, is determined by the ebb and flow of the market. Limit orders thus have execution uncertainty.
A few additional important order types
- Market-not-held order. This type of order is relevant for trades placed on certain exchanges (regulated trading venues) where an order may be handled by an agent of the trader in executing trades (a broker). This variation of the market order is designed to give the agent greater discretion than a simple market order would allow. “Not held” means that the broker is not required to trade at any specific price or in any specific time interval, as would be required with a simple market order. Discretion is placed in the hands of a representative of the broker (such as a floor broker—an agent of the broker who, for certain exchanges, physically represents the trade on the exchange). The broker may choose not to participate in the flow of orders on the exchange if the broker believes he or she will be able to get a better price in subsequent trading.
- Participate (do not initiate) order. This is a variant of the market-not-held order. The broker is to be deliberately low-key and wait for and respond to initiatives of more active traders. Buy-side traders who use this type of order hope to capture a better price in exchange for letting the other side determine the timing of the trade.
- Best efforts order. This type of order gives the trader’s agent even more discretion to work the order only when the agent judges market conditions to be favorable. Some degree of immediacy is implied, but not immediacy at any price.
- Undisclosed limit order, also known as a reserve, hidden, or iceberg order. This is a limit order that includes an instruction not to show more than some maximum quantity of the unfilled order. For example, a trader might want to buy 200,000 shares of an issue traded on Euronext Amsterdam. The order size would represent a substantial fraction of average daily volume in the issue, and the trader is concerned that share price might move up if the full extent of his or her interest were known. The trader places an undisclosed limit order to buy the 200,000 shares, specifying that no more than 20,000 shares of the unfilled order be shown to the public at a time.
- Market on open order. This is a market order to be executed at the opening of the market. Similarly, a market on close order is a market order to be executed at the market close. These are examples of orders with an instruction for execution at a specific time. The rationale for using these two types of orders is that the opening and close in many markets provide good liquidity.
Special types of trades
- Principal trade. A principal trade is a trade with a broker in which the broker commits capital to facilitate the prompt execution of the trader’s order to buy or sell. Principal trades are used most frequently when the order is larger and/or more urgent than can be accommodated within the normal ebb and flow of exchange trading. A price concession provides an incentive for the broker acting as a principal in the trade.
- Portfolio trade (or program trade or basket trade). A portfolio trade involves an order that requires the execution of purchases (or sales) in a specified basket (list) of securities at as close to the same time as possible. For example, an S&P 500 index fund manager with new cash to invest could execute a portfolio trade to buy the S&P 500 (the shares in the S&P 500 in their index weights). Portfolio trades are often relatively low cost because the diversification implied by multiple security issues reduces the risk to the other side of the trade.
Markets are organized to provide? (main features)
Markets are organized to provide:
- liquidity (the ability to trade without delay at relatively low cost and in relatively large quantities),
- transparency (availability of timely and accurate market and trade information),
- assurity of completion (trades settle without problems under all market conditions—trade settlement involves the buyer’s payment for the asset purchased and the transfer of formal ownership of that asset).
Chief ways trading is organized
The chief ways trading is organized:
- Quote-driven (or dealer) markets, in which members of the public trade with dealers rather than directly with one another.
- Order-driven markets, in which members of the public trade with one another without the intermediation of dealers.
- Brokered markets, in which the trader relies on a broker to find the other side of a desired trade.
Main trends in markets
Fixed-income and equity markets have evolved very rapidly over the 1990s and 2000s. There are many more choices as to where to trade such bonds and equities than was the case historically—a phenomenon that has been called market fragmentation.
Another trend is the increasing amount of trading that is partly or fully automated, in the sense that the execution of a trader’s order after entry requires minimal or no human intervention or trader-to-trader communication. Reflecting the concern to minimize settlement errors and costs in security markets, the settlement of the trade after execution may also be automated within a given trading system or venue (straight-through processing, or STP).
Quote-Driven (Dealer) Markets
Quote-driven markets rely on dealers to establish firm prices at which securities can be bought and sold. These markets are therefore also called dealer markets, as trades are executed with a dealer. A dealer (sometimes referred to as a market maker) is a business entity that is ready to buy an asset for inventory or sell an asset from inventory to provide the other side of an order to buy or sell the asset.
In the traditional view, market makers or dealers passively provide immediacy or bridge liquidity, the price of which is the bid–ask spread (the ask price minus the bid price). A dealer’s (or any trader’s) bid price (or bid) is the price at which he or she will buy a specified quantity of a security. A dealer’s (or any trader’s) ask price (or ask, or offer price, or offer) is the price at which he or she will sell a specified quantity of a security. On the principle of buying low and selling high, a dealer’s ask price is greater than his bid price. The quantity associated with the bid price is often referred to as the bid size; the quantity associated with the ask price is known as the ask size. From the perspective of a trader executing an order to buy a security from a dealer, a lower ask from the dealer is favorable to the trader. If the trader is executing an order to sell a security to a dealer, a higher bid from the dealer is favorable to the trader.
Dealers can help markets operate continuously. Bond markets, in particular, are overwhelmingly dealer markets. The explanation lies in a lack of natural liquidity for many bonds. (Natural liquidity is an extensive pool of investors who are aware of and have a potential interest in buying and/or selling a security.) Many bonds are extremely infrequently traded. If an investor wanted to buy such a bond, the investor might have a very long wait before the other side of the trade (an interest to sell) appeared from the public.
Effective spread
The size of the quoted bid–ask spread (reflecting the market quote), particularly as a proportion of the quote midpoint, is one measure of trading costs. However, the quoted bid–ask spread may be different from the spread at which a trader actually transacts. The trader’s focus is therefore often on the effective spread.
The effective spread is two times the deviation of the actual execution price from the midpoint of the market quote at the time an order is entered. (If parts of the order execute at different prices, the weighted-average execution price is used in computing the deviation from the midpoint.) The quoted spread is the simplest measure of round-trip transaction costs for an average-size order. The effective spread is a better representation of the true cost of a round-trip transaction because it captures both price improvement (i.e., execution within the quoted spread at a price such that the trader is benefited) and the tendency for larger orders to move prices (market impact).
The price improvement has resulted in an effective spread that is lower than the quoted spread.
The average effective spread is the mean effective spread (sometimes dollar weighted) over all transactions in the stock in the period under study. The average effective spread attempts to measure the liquidity of a security’s market.
! The difference between quoted spreads and effective spreads reflects the price improvement provided by dealers. If the effective spreads are lower than the quoted spreads, dealers are providing price improvements.
Order-Driven Markets
Order-driven markets are markets in which transaction prices are established by public limit orders to buy or sell a security at specified prices. Such markets feature trades between public investors, usually without intermediation by designated dealers (market makers).
For equity markets, a worldwide trend has favored order-driven markets at the expense of quote-driven markets. Various types of order-driven markets are distinguished:
1. Electronic Crossing Networks
In using crossing networks, both buyer and seller avoid the costs of dealer services (the bid–ask spread), the effects a large order can have on execution prices, and information leakage. Commissions are paid to the crossing network but are typically low. However, crossing participants cannot be guaranteed that their trades will find an opposing match: The volume in a crossing system is determined by the smallest quantity submitted.
Crossing networks provide no price discovery. Price discovery means that transaction prices adjust to equilibrate supply and demand.
! Crossing networks maintain complete confidentiality not only in regard to the size of the orders and the names of the investors placing the orders, but also in regard to the unmatched quantities.
2. Auction Markets
Many order-driven markets are auction markets—that is, markets in which the orders of multiple buyers compete for execution. Auction markets can be further categorized into periodic auction markets or batch auction markets (where multilateral trading occurs at a single price at a prespecified point in time) and continuous auction markets (where orders can be executed at any time during the trading day).
In contrast to electronic crossing markets, auction markets provide price discovery, lessening the problem of partial fills that we illustrated above for crossing networks.
3. Automated Auctions (Electronic Limit-Order Markets)
Electronic communications networks (ECNs) - these are computer-based auctions that operate continuously within the day using a specified set of rules to execute orders.
Automated auctions have been among the fastest-growing segments in equity trading. ECNs in particular have blurred the traditional difference between order-driven markets and quote-driven dealer markets. In an ECN, it can be difficult to distinguish between participants who are regulated, professional dealers and other participants who, in effect, are also attempting to earn spread profits by providing liquidity. Hedge funds or day traders, for example, might actively supply liquidity to the market to capture the dealer-like spread profits. From the perspective of an investor, the result is added liquidity and tighter spreads.
Brokered Markets
A broker is an agent of the buy-side trader who collects a commission for skillful representation of the trade. The broker may represent the trade to dealers in the security or to the market order flow. However, the term brokered markets refers specifically to markets in which transactions are largely effected through a search-brokerage mechanism away from public markets. Typically, these markets are important in countries where the underlying public markets (e.g., stock exchanges) are relatively small or where it is difficult to find liquidity in size. Consequently, brokered markets are mostly used for block transactions.
A block order is an order to sell or buy in a quantity that is large relative to the liquidity ordinarily available from dealers in the security or in other markets. The trader might use the services of a broker to carefully try to uncover the other side of the trade in return for a commission; the broker might occasionally position a portion of the block. (To position a trade is to take the other side of it, acting as a principal with capital at risk.) Brokers can also provide a reputational screen to protect uninformed or liquidity-motivated traders. For example, the broker might “shop the block” only to those potential counterparties that the broker believes are unlikely to front-run the trade (trade ahead of the initiator, exploiting privileged information about the initiator’s trading intentions). These attributes of brokerage markets facilitate trading and hence add value for all parties to the transaction.
Hybrid Markets
Hybrid markets are combinations of the previously described market types. A good example is the New York Stock Exchange (NYSE), which offers elements of batch auction markets (e.g., the opening) and continuous auction markets (intraday trading), as well as quote-driven markets (the important role of NYSE dealers, who are known as specialists).
The Roles of Brokers
A broker is an agent of the investor. As such, in return for a commission, the broker provides various execution services, including the following:
- Representing the order. The broker’s primary task is to represent the order to the market. The market will accommodate, usually for a price, someone who feels he or she must trade immediately.
- Finding the opposite side of a trade. If interest in taking the opposite side of a trade is not currently evident in the market, it usually falls to the broker to try to locate the seller for the desired buy, or the buyer for the desired sale. Often this service requires that the broker act as a dealer and actively buy or sell shares for the broker’s own account. The broker/dealer does not bear risk without compensation. Depending on the dealer’s inventory position, this service may come at a high cost.
- Supplying market information. Market information includes the identity of buyers and sellers, the strength of buying and selling interest, and other information that is relevant to assessing the costs and risks of trading. This market intelligence, which can be provided by the broker, is very valuable to buy-side traders as they consider their trading tactics.
- Providing discretion and secrecy. Buy-side traders place great value on preserving the anonymity of their trading intentions. Notice, however, that such secrecy does not extend to the selected broker, whose stock in trade is the knowledge of supply and demand. That an investor is willing to trade is a very valuable piece of information the broker gains as result of his or her relationship with the trader.
- Providing other supporting investment services. A broker may provide a range of other services, including providing the client with financing for the use of leverage, record keeping, cash management, and safekeeping of securities. A particularly rich set of supporting services, often including introduction to potential clients, is provided in relationships that have come to be known as prime brokerage.
- Supporting the market mechanism. Brokerage commissions indirectly assure the continuance of the needed market facilities.
The Roles of Dealers
In contrast to the agency relationship of the broker with the trader, the relationship between the trader and a dealer is essentially adversarial. Like any other merchant, the dealer wants to sell merchandise at a higher price (the ask) than the purchase price (the bid). Holding trade volume constant, a dealer gains by wider bid–ask spreads while the trader gains by narrower bid–ask spreads. The dealer is wary of trading with a better-informed counterparty.
Adverse selection risk - the risk of trading with a more informed trader.
Dealers want to know who is active in the market, how informed traders are, and how urgent their interest in transacting with the dealer is, in order to manage profits and adverse selection risk. The tension occurs because the informed or urgent trader does not want the dealer to know those facts.
Buy-side traders are often strongly influenced by sell-side traders such as dealers (the sell side consists of institutions that sell services to firms such as investment managers and institutional investors).
Characteristics of liquid markets
A liquid market is one that has the following characteristics:
- The market has relatively low bid–ask spreads. Such a market is often called tight. Quoted spreads and effective spreads are low. The costs of trading small amounts of an asset are themselves small. As a result, investors can trade positions without excessive loss of value. If bid–ask spreads are high, investors cannot profitably trade on information except when the information is of great value.
- The market is deep. Depth means that big trades tend not to cause large price movements. As a result, the costs of trading large amounts of an asset are relatively small. Deep markets have high quoted depth, which is the number of shares available for purchase or sale at the quoted bid and ask prices.
- The market is resilient. A market is resilient (in the sense used here) if any discrepancies between market price and intrinsic value tend to be small and corrected quickly.
Factors that contribute to making a market liquid
Liquidity adds value to the companies whose securities trade on the exchange. Investors will pay a premium for securities that possess the valuable trait of liquidity. Higher security prices enhance corporate value and lower the cost of capital.
Many factors contribute to making a market liquid:
- Many buyers and sellers. The presence of many buyers and sellers increases the chance of promptly locating the opposite side of a trade at a competitive price. Success breeds success in that the liquidity resulting from many buyers and sellers attracts additional participants to the market. Investors are more willing to hold shares that they can dispose of whenever they choose to do so.
- Diversity of opinion, information, and investment needs among market participants. If the investors in a given market are highly alike, they are likely to want to take similar investment actions and make similar trades. Diversity in the factors described above increases the chance that a buyer of a security, who might have a positive opinion about it, can find a seller, who might have a negative opinion about it or a need for cash. In general, a large pool of investors enhances diversity of opinion.
- Convenience. A readily accessible physical location or an easily mastered and well-thought-out electronic platform attracts investors.
- Market integrity. Investors who receive fair and honest treatment in the trading process will trade again. The ethical tone set by professional market operatives plays a major role in establishing this trust, as does effective regulation. For example, audits of the financial condition and regulatory compliance of brokers and dealers operating in a market increase public confidence in the market’s integrity, as do procedures for the disinterested investigation of complaints about the execution of trades.
Transaction Cost Components
Trading costs can be thought of as having two major components: explicit costs and implicit costs. Explicit costs are the direct costs of trading, such as broker commission costs, taxes, stamp duties, and fees paid to exchanges. They are costs for which a trader could be given a receipt. Implicit costs, by contrast, represent indirect trading costs. No receipt could be given for implicit costs; they are real nonetheless. Implicit costs include the following:
- The bid–ask spread.
- Market impact (or price impact) is the effect of the trade on transaction prices.
- Missed trade opportunity costs (or unrealized profit/loss) arise from the failure to execute a trade in a timely manner. Missed trade opportunity costs are difficult to measure.
- Delay costs (also called slippage) arise from the inability to complete the desired trade immediately due to its size and the liquidity of markets. Delay costs are often measured on the portion of the order carried over from one day to the next. One reason delay can be costly is that while a trade is being stretched out over time, information is leaking into the market.
VWAP
Most traders measure implicit costs (i.e., costs excluding commissions) with reference to some price benchmark or reference point. We have already mentioned one price benchmark: the time-of-trade midquote (quotation midpoint), which is used to calculate the effective spread. When such precise information is lacking, the price benchmark is sometimes taken to be the volume-weighted average price (VWAP). The VWAP of a security is the average price at which the security traded during the day, where each trade price is weighted by the fraction of the day’s volume associated with the trade. The VWAP is an appealing price benchmark because it allows the fund sponsor to identify when it transacted at a higher or lower price than the security’s average trade price during the day.
VWAP is less informative for trades that represent a large fraction of volume. In the extreme, if a single trading desk were responsible for all the buys in a security during a day, that desk’s average price would equal VWAP and thus appear to be good, however high the prices paid. Another limitation of VWAP (and of the effective spread) is that a broker with sufficient discretion can try to “game” this measure. (To game a cost measure is to take advantage of a weakness in the measure, so that the value of the measure may be misleading.)
In contrast to the VWAP, which is partly determined as the trading day progresses, the opening price is known with certainty at any point into the trading day, making it easier to game.
To address the possibility of gaming VWAP, VWAP could be measured over multiple days (spanning the time frame over which the order is executed), because traders would often be expected to try to execute trades within a day. However, the cost of measuring VWAP over a longer time frame is less precision in estimating trading costs.
If the trade is of low urgency and can be traded over time it is thus suitable for VWAP based strategy.
+ VWAP does not consider missed trades!!!
Implementation shortfall approach
Probably the most exact approach to cost measurement—and one not vulnerable to gaming—is the implementation shortfall approach. The approach involves a comparison of the actual portfolio with a paper portfolio, using a price benchmark that represents the price when the decision to trade is made (when the trade list is cut).
Implementation shortfall is defined as the difference between the money return on a notional or paper portfolio in which positions are established at the prevailing price when the decision to trade is made (known as the decision price, the arrival price, or the strike price) and the actual portfolio’s return. The implementation shortfall method correctly captures all elements of transaction costs. The method takes into account not only explicit trading costs, but also the implicit costs, which are often significant for large orders.
Implementation shortfall can be analyzed into four components:
- Explicit costs, including commissions, taxes, and fees.
- Realized profit/loss, reflecting the price movement from the decision price (usually taken to be the previous day’s close) to the execution price for the part of the trade executed on the day it is placed.
- Delay costs (slippage), reflecting the change in price (close-to-close price movement) over the day an order is placed when the order is not executed that day; the calculation is based on the amount of the order actually filled subsequently.
- Missed trade opportunity cost (unrealized profit/loss), reflecting the price difference between the trade cancellation price and the original benchmark price based on the amount of the order that was not filled
The shortfall computation is simply reversed for sells (for sells, the return on the paper portfolio is subtracted from the return on the actual portfolio).