pre_text: 4. Cash and Cash Equivalents The following table summarizes the components of our cash and cash equivalents (amounts in millions):
table: At December 31,
table: 2019 2018
table: Cash $437 $268
table: Foreign government treasury bills 37 32
table: Money market funds 5,320 3,925
table: Cash and cash equivalents $5,794 $4,225
question: Analyse this data from a financial earnings document. What was the change in money market funds between 2018 and 2019?