E. I. du Pont de Nemours and Company Notes to the Consolidated Financial Statements (continued) NOTE 21 - FAIR VALUE MEASUREMENTS The following tables summarize the basis used to measure certain assets and liabilities at fair value on a recurring basis: December 31, 2018 Significant Other Observable Inputs (Level 2) (In millions) Assets at fair value: Cash equivalents and restricted cash equivalents 1 $ 3,551 Marketable securities 34 Derivatives relating to: 2 Foreign currency 72 Total assets at fair value $ 3,657 Liabilities at fair value: Long-term debt 3 $ 6,100 Derivatives relating to: 2 Foreign currency 21 Total liabilities at fair value $ 6,121 December 31, 2017 Significant Other Observable Inputs (Level 2) (In millions) Assets at fair value: Cash equivalents and restricted cash equivalents 1 $ 5,205 Marketable securities 952 Derivatives relating to: 2 Foreign currency 46 Total assets at fair value $ 6,203 Liabilities at fair value: Long-term debt 3 $ 11,560 Derivatives relating to: 2 Foreign currency 79 Total liabilities at fair value $ 11,639 1.Time deposits included in cash and cash equivalents and money market funds included in other current assets in the consolidated balance sheets are held at amortized cost, which approximates fair value. 2.See Note 20 for the classification of derivatives in the consolidated balance sheets. 3.See Note 15 for information on fair value measurements of long-term debt. For assets and liabilities classified as Level 1 measurements (measured using quoted prices in active markets), total fair value is either the price of the most recent trade at the time of the market close or the official close price, as defined by the exchange on which the asset is most actively traded on the last trading day of the period, multiplied by the number of units held without consideration of transaction costs. For assets and liabilities classified as Level 2 measurements, where the security is frequently traded in less active markets, fair value is based on the closing price at the end of the period; where the security is less frequently traded, fair value is based on the price a dealer would pay for the security or similar securities, adjusted for any terms specific to that asset or liability, or by using observable market data points of similar, more liquid securities to imply the price. For time deposits classified as held-to-maturity investments and reported at amortized cost, fair value is based on an observable interest rate for similar securities. Market inputs are obtained from well-established and recognized vendors of market data and subjected to tolerance and quality checks.  For derivative assets and liabilities, standard industry models are used to calculate the fair value of the various financial instruments based on significant observable market inputs, such as foreign exchange rates, commodity prices, swap rates, interest rates and implied volatilities obtained from various market sources. Market inputs are obtained from well-established and recognized vendors of market data and subjected to tolerance/quality checks. F-78