PnL Explained also called P&L Explain, P&L Attribution or Profit and Loss Explained is a type of report commonly used by traders, especially derivative

Derivative

In calculus, a branch of mathematics, the derivative is a measure of how a function changes as its input changes. Loosely speaking, a derivative can be thought of as how much one quantity is changing in response to changes in some other quantity; for example, the derivative of the position of a...

s (swaps

Swap (finance)

In finance, a swap is a derivative in which counterparties exchange certain benefits of one party's financial instrument for those of the other party's financial instrument. The benefits in question depend on the type of financial instruments involved...

 and options

Option (finance)

In finance, an option is a derivative financial instrument that specifies a contract between two parties for a future transaction on an asset at a reference price. The buyer of the option gains the right, but not the obligation, to engage in that transaction, while the seller incurs the...

) traders, that attributes or explains the daily fluctuation in the value of a portfolio of trades to the root causes of the changes.

P&L is the day-over-day change in the value of a portfolio of trades typically calculated using the following formula:
PnL = Value today - Value from Prior Day

Report

A PnL Explained Report will usually contain one row per trade or group of trades and will have at a minimum these columns:

• Column 1: PnL --- This is the PnL as calculated outside of the PnL Explained report
• Column 2: PnL Explained --- This is the sum of the explanatory columns
• Column 3: PnL Unexplained --- This is calculated as PnL - PnL Explained (i.e., Column 1 - Column 2)
• Column 4: Impact of Time --- This is the PnL due to the change in time.
• Column 5: Impact of Prices --- This is the PnL, i.e., the change in the value of a portfolio due to changes in commodity or equity/stock prices
• Column 6: Impact of Interest Rates --- This is the PnL due to changes in interest rates
• Column 7: Impact of Volatility --- This is the PnL due to changes in volatilities. Volatilities are used to value Option (finance)
  Option (finance)
  In finance, an option is a derivative financial instrument that specifies a contract between two parties for a future transaction on an asset at a reference price. The buyer of the option gains the right, but not the obligation, to engage in that transaction, while the seller incurs the...
  
  (i.e., calls and puts)
• Column 8: Impact of New Trades --- PnL from trades done on the current day
• Column 9: Impact of Cancellation / Amendment - PnL from trades cancelled or changed on the current day

Methodologies

There are two methodologies for calculating Pnl Explained, the 'sensitivities' method and the 'revaluation' method.

Sensitivities method

1) The Sensitivities Method involves first calculating option sensitivities known as the Greeks because of the common practice of representing the sensitivities using Greek letters. For example, the delta of an option is the value an option changes due to a $0.01 move in the underlying commodity or equity/stock. To calculate 'Impact of Prices' the formula is

• Impact of Prices = Option Delta * Price Move

so if the price moves $100 and the option's delta is 0.05% then the 'Impact of Prices' is $100.05.

Revaluation method

2) The Revaluation Method recalculates the value of a trade based on the current and the prior day's prices. The formula for Impact of Prices using the Revaluation Method is

• Impact of Prices = (Trade Value using Today's Prices) - (Trade Value using Prior Day's Prices)

External links

• PnL Explained Professionals Information and examples from PnL Explained Professionals Association's home page
• Energy Risk Magazine Articles on PnL Explained from Energy Risk Magazine