The market risk associated with the company's portfolio of financial and derivative instruments is discussed below. The estimates of financial exposure to market risk discussed below do not represent the company's projection of future market changes. The actual impact of future market changes could differ materially due to factors discussed elsewhere in this report, including those set forth under the heading "Risk Factors" in Part I, Item 1A, of the company's 2008 Annual Report on Form 10-K.
Derivative Commodity Instruments
Chevron is exposed to market risks related to the price volatility of crude oil, refined products, natural gas, natural gas liquids, liquefied natural gas and refinery feedstocks.
The company uses derivative commodity instruments to manage these exposures on a portion of its activity, including firm commitments and anticipated transactions for the purchase, sale and storage of crude oil, refined products, natural gas, natural gas liquids and feedstock for company refineries. The company also uses derivative commodity instruments for limited trading purposes. The results of this activity were not material to the company's financial position, net income or cash flows in 2008.
The company's market exposure positions are monitored and managed on a daily basis by an internal Risk Control group to ensure compliance with the company's risk management policies that have been approved by the Audit Committee of the company's Board of Directors.
The derivative instruments used in the company's risk management and trading activities consist mainly of futures, options and swap contracts traded on the NYMEX (New York Mercantile Exchange) and on electronic platforms of ICE (Inter-Continental Exchange) and GLOBEX (Chicago Mercantile Exchange). In addition, crude oil, natural gas and refined-product swap contracts and option contracts are entered into principally with major financial institutions and other oil and gas companies in the "over-the-counter" markets.
Virtually all derivatives beyond those designated as normal purchase and normal sale contracts are recorded at fair value on the Consolidated Balance Sheet with resulting gains and losses reflected in income. Fair values are derived principally from published market quotes and other independent third-party quotes. The change in fair value from Chevron's derivative commodity instruments in 2008 was a quarterly average increase of $160 million in total assets and a quarterly average decrease of $1 million in total liabilities.
The company uses a Value-at-Risk (VaR) model to estimate the potential loss in fair value on a single day from the effect of adverse changes in market conditions on derivative instruments held or issued, which are recorded on the balance sheet at December 31, 2008, as derivative instruments in accordance with FAS Statement No. 133, "Accounting for Derivative Instruments and Hedging Activities," as amended (FAS 133). VaR is the maximum loss not to be exceeded within a given probability or confidence level over a given period of time. The company's VaR model uses the Monte Carlo simulation method that involves generating hypothetical scenarios from the specified probability distribution and constructing a full distribution of a portfolio's potential values.
The VaR model utilizes an exponentially weighted moving average for computing historical volatilities and correlations, a 95 percent confidence level, and a one-day holding period. That is, the company's 95 percent, one-day VaR corresponds to the unrealized loss in portfolio value that would not be exceeded on average more than one in every 20 trading days, if the portfolio were held constant for one day.
The one-day holding period is based on the assumption that market-risk positions can be liquidated or hedged within one day. For hedging and risk management, the company uses conventional exchange-traded instruments such as futures and options as well as non-exchange-traded swaps, most of which can be liquidated or hedged effectively within one day. The table below presents the 95 percent/one-day VaR for each of the company's primary risk exposures in the area of derivative commodity instruments at December 31, 2008 and 2007. The higher amounts in 2008 were associated with an increase in price volatility for these commodities during the year.
| Millions of dollars |
2008 |
2007 |
| Crude Oil |
$ 39 |
$ 29 |
| Natural Gas |
5 |
3 |
| Refined Products |
45 |
23 |
Foreign Currency
The company enters into forward exchange contracts, generally with terms of 180 days or less, to manage some of its foreign currency exposures. These exposures include revenue and anticipated purchase transactions, including foreign currency capital expenditures and lease commitments, forecasted to occur within 180 days. The forward exchange contracts are recorded at fair value on the balance sheet with resulting gains and losses reflected in income.
The aggregate effect of a hypothetical 10 percent increase in the value of the U.S. dollar at year-end 2008 would be a reduction in the fair value of the foreign exchange contracts of approximately $100 million. The effect would be the opposite for a hypothetical 10 percent decrease in the value of the U.S. dollar at year-end 2008.
Interest Rates
The company enters into interest-rate swaps from time to time as part of its overall strategy to manage the interest-rate risk on its debt. Under the terms of the swaps, net cash settlements are based on the difference between fixed-rate and floating-rate interest amounts calculated by reference to agreed notional principal amounts. Interest-rate swaps related to a portion of the company's fixed-rate debt are accounted for as fair value hedges. Interest-rate swaps related to floatingrate debt are recorded at fair value on the balance sheet with resulting gains and losses reflected in income. At year-end 2008, the company had no interest-rate swaps on floating-rate debt. The company's only interest-rate swaps on fixed-rate debt matured in January 2009.