We use futures, forwards, swaps and options in various markets to meet our customer needs, capture market opportunities and manage foreign exchange currency risk.

Commodity derivative instruments are held at fair value on our consolidated balance sheet. Where these balances have the right of setoff, they are presented on a net basis. Related cash flows are recorded as operating activities on our consolidated statement of cash flows. On our consolidated income statement, gains and losses are recognized either on a gross basis if directly related to our physical business or a net basis if held for trading. Gains and losses related to contracts that meet and are designated with the NPNS exception are recognized upon settlement. We generally apply this exception to eligible crude contracts and certain gas contracts. We do not apply hedge accounting for our commodity derivatives.

The following table presents the gross fair values of our commodity derivatives, excluding collateral, and the line items where they appear on our consolidated balance sheet:


	Millions of Dollars
	March 31 2023		December 31 2022
Assets
Prepaid expenses and other current assets	$	983	1,795
Other assets	235		242
Liabilities
Other accruals	969		1,800
Other liabilities and deferred credits	198		210


	Open Position Long (Short)
	March 31 2023	December 31 2022
Commodity
Natural gas and power (billions of cubic feet equivalent)
Fixed price	(16)	(14)
Basis	(39)	(8)

We invest in financial instruments with maturities based on our cash forecasts for the various accounts and currency pools we manage. The types of financial instruments in which we currently invest include:

•Commercial paper: Unsecured promissory notes issued by a corporation, commercial bank or government agency purchased at a discount, reaching par value at maturity.

The following investments are carried on our consolidated balance sheet at cost, plus accrued interest, and the table reflects remaining maturities at March 31, 2023, and December 31, 2022:


	Millions of Dollars
	Carrying Amount
	Cash and Cash Equivalents			Short-Term Investments
	March 31 2023		December 31 2022	March 31 2023	December 31 2022
Cash	$	676	593
Demand Deposits	1,174		1,638
Time Deposits
1 to 90 days	4,257		4,116	985	1,288
91 to 180 days				16	883
Within one year				91	11
U.S. Government Obligations
1 to 90 days	754		14	—	—
	$	6,861	6,361	1,092	2,182

The following investments in debt securities classified as available for sale are carried at fair value on our consolidated balance sheet at March 31, 2023, and December 31, 2022:


	Millions of Dollars
	Carrying Amount
	Cash and Cash Equivalents			Short-Term Investments		Investments and Long-Term Receivables
	March 31 2023		December 31 2022	March 31 2023	December 31 2022	March 31 2023	December 31 2022
Major Security Type
Corporate Bonds	$	—	—	307	323	391	309
Commercial Paper	101		97	136	156
U.S. Government Obligations	12		—	87	115	96	63
U.S. Government Agency Obligations				13	8	7	5
Foreign Government Obligations				—	—	7	7
Asset-backed Securities				—	1	111	138
	$	113	97	543	603	612	522


	Millions of Dollars
	Amortized Cost Basis			Fair Value
	March 31 2023		December 31 2022	March 31 2023	December 31 2022
Major Security Type
Corporate Bonds	$	705	641	698	632
Commercial Paper	237		253	237	253
U.S. Government Obligations	197		181	195	178
U.S. Government Agency Obligations	20		13	20	13
Foreign Government Obligations	7		7	7	7
Asset-backed Securities	112		139	111	139
	$	1,278	1,234	1,268	1,222

As of March 31, 2023 and December 31, 2022, total unrealized losses for debt securities classified as available for sale with net losses were $11 million and $12 million, respectively. No allowance for credit losses has been recorded on investments in debt securities which are in an unrealized loss position.

For the three-month periods ended March 31, 2023 and March 31, 2022, proceeds from sales and redemptions of investments in debt securities classified as available for sale were $300 million and $115 million, respectively. Gross realized gains and losses included in earnings from those sales and redemptions were negligible. The cost of securities sold and redeemed is determined using the specific identification method.

Financial instruments potentially exposed to concentrations of credit risk consist primarily of cash equivalents, short-term investments, long-term investments in debt securities, OTC derivative contracts and trade receivables. Our cash equivalents and short-term investments are placed in high-quality commercial paper, government money market funds, U.S. government and government agency obligations, time deposits with major international banks and financial institutions, high-quality corporate bonds, foreign government obligations and asset-backed securities. Our long-term investments in debt securities are placed in high-quality corporate bonds, asset-backed securities, U.S. government and government agency obligations, and foreign government obligations.

The credit risk from our OTC derivative contracts, such as forwards, swaps and options, derives from the counterparty to the transaction. Individual counterparty exposure is managed within predetermined credit limits and includes the use of cash-call margins when appropriate, thereby reducing the risk of significant nonperformance. We also use futures, swaps and option contracts that have a negligible credit risk because these trades are cleared primarily with an exchange clearinghouse and subject to mandatory margin requirements until settled; however, we are exposed to the credit risk of those exchange brokers for receivables arising from daily margin cash calls, as well as for cash deposited to meet initial margin requirements.

Our trade receivables result primarily from our oil and gas operations and reflect a broad national and international customer base, which limits our exposure to concentrations of credit risk. The majority of these receivables have payment terms of 30 days or less, and we continually monitor this exposure and the creditworthiness of the counterparties. We may require collateral to limit the exposure to loss including letters of credit, prepayments and surety bonds, as well as master netting arrangements to mitigate credit risk with counterparties that both buy from and sell to us, as these agreements permit the amounts owed by us or owed to others to be offset against amounts due to us.

Certain of our derivative instruments contain provisions that require us to post collateral if the derivative exposure exceeds a threshold amount. We have contracts with fixed threshold amounts and other contracts with variable threshold amounts that are contingent on our credit rating. The variable threshold amounts typically decline for lower credit ratings, while both the variable and fixed threshold amounts typically revert to zero if we fall below investment grade. Cash is the primary collateral in all contracts; however, many also permit us to post letters of credit as collateral, such as transactions administered through the New York Mercantile Exchange.

The aggregate fair value of all derivative instruments with such credit risk-related contingent features that were in a liability position at March 31, 2023 and December 31, 2022, was $166 million and $333 million, respectively. For these instruments, no collateral was posted at March 31, 2023 and $42 million of collateral was posted at December 31, 2022. If our credit rating had been downgraded below investment grade at March 31, 2023, we would have been required to post $140 million of additional collateral, either with cash or letters of credit.