Table:
|  | December 31, 2019 |  | December 31, 2018 |  |
| --- | --- | --- | --- | --- |
|  | Carrying Value | Fair Value | Carrying Value | Fair Value |
|  |  | (in thousands) |  |  |
| Assets |  |  |  |  |
| Cash and cash equivalents | $773,924 | $773,924 | $926,752 | $926,752 |
| Marketable securities | 241,793 | 241,793 | 277,827 | 277,827 |
| Derivative assets | 528 | 528 | 79 | 79 |
| Liabilities |  |  |  |  |
| Contingent consideration | 39,705 | 39,705 | 70,543 | 70,543 |
| Derivative liabilities | 203 | 203 | 514 | 514 |
| Convertible debt (1) | 394,687 | 1,010,275 | 379,981 | 547,113 |
Paragraphs:
The carrying amounts and fair values of Teradyne’s financial instruments at December 31, 2019 and 2018 were as follows:
(1) The carrying value represents the bifurcated debt component only, while the fair value is based on quoted market prices for the convertible note which includes the equity conversion features.
The fair values of accounts receivable, net and accounts payable approximate the carrying amount due to the short term nature of these instruments.
Question:
What was the change in the fair value of Marketable securities from 2018 to 2019?
Answer: 241793-277827 = -36034