Implementation shortfall
Encyclopedia
In financial markets, Implementation Shortfall is the difference between the decision price and the final execution price (including commissions, taxes, etc.) for a trade. This is also known as the "slippage". Agency trading is largely concerned with minimizing implementation shortfall and finding liquidity.
From the fund manager's point of view, his decision to trade is often based on the closing price of the day's trading (along with the entire history of the stock and other signals/indicators). When he decides to buy a particular stock the next day, it is because he believes that the price will go up from that closing price. Thus his decision price is the close price.
However the broker, unless she is explicitly told what levels to buy at or what prompted the desire to buy, does not know when or why the decision was made. Her best guess is that the current price at the time the order is received is what prompted the decision and thus her decision price is the arrival price. There is no common definition of this price, but the broker normally uses the last traded price or the "mid price" - equal to the average of the current bid and ask prices being quoted at the time the order was received.
Brokerage firms specialize in developing algorithmic strategies, and providing them to the institutional investment community, that aid in the quest to outperform benchmarks such as Implementation Shortfall.
Decision Price
The decision price is the price of the stock that prompted the decision to buy or sell. The most common decision prices is the close price or the arrival price. If we split the decision to buy a stock from the actual trading of the stock, as is often the case with fund managers (decision makers) and brokers (trade executors), you can see why both are used.From the fund manager's point of view, his decision to trade is often based on the closing price of the day's trading (along with the entire history of the stock and other signals/indicators). When he decides to buy a particular stock the next day, it is because he believes that the price will go up from that closing price. Thus his decision price is the close price.
However the broker, unless she is explicitly told what levels to buy at or what prompted the desire to buy, does not know when or why the decision was made. Her best guess is that the current price at the time the order is received is what prompted the decision and thus her decision price is the arrival price. There is no common definition of this price, but the broker normally uses the last traded price or the "mid price" - equal to the average of the current bid and ask prices being quoted at the time the order was received.
Brokerage firms specialize in developing algorithmic strategies, and providing them to the institutional investment community, that aid in the quest to outperform benchmarks such as Implementation Shortfall.
See also
- Algorithmic TradingAlgorithmic tradingIn electronic financial markets, algorithmic trading or automated trading, also known as algo trading, black-box trading or robo trading, is the use of electronic platforms for entering trading orders with an algorithm deciding on aspects of the order such as the timing, price, or quantity of the...
- Algorithmic Trading Platforms
- Market ImpactMarket impactIn financial markets, market impact is the effect that a market participant has when it buys or sells an asset. It is the extent to which the buying or selling moves the price against the buyer or seller, i.e. upward when buying and downward when selling...