Table:
|  | 2019 | 2018 | 2017 |
| --- | --- | --- | --- |
| Net cash provided by (used in) operating activities | $174,201 | $(326,809) | $1,340,677 |
| Net cash used in investing activities | (362,298) | (682,714) | (626,802) |
| Net cash provided by financing activities | 74,943 | 255,228 | 192,045 |
| Effect of exchange rate changes on cash, cash equivalents and restricted cash. | (2,959) | (13,558) | 8,866 |
| Net (decrease) increase in cash, cash equivalents and restricted cash | $(116,113) | $(767,853) | $914,786 |
Paragraphs:
Cash Flows
The following table summarizes key cash flow activity for the years ended December 31, 2019, 2018, and 2017 (in thousands):
Operating Activities
The increase in net cash provided by operating activities during 2019 was primarily driven by higher cash proceeds from sales of systems projects, including the Sunshine Valley, Sun Streams, and California Flats projects, and advance payments received for sales of solar modules prior to the step down in the U.S. investment tax credit as discussed above. These increases were partially offset by operating expenditures associated with initial ramp of certain Series 6 manufacturing lines and expenditures for the construction of certain projects.
Investing Activities
The decrease in net cash used in investing activities during 2019 was primarily due to higher net sales of marketable securities and restricted investments, partially offset by proceeds associated with the sale of our interests in 8point3 and its subsidiaries in 2018.
Financing Activities
The decrease in net cash provided by financing activities during 2019 was primarily the result of lower net proceeds from borrowings under project specific debt financings associated with the construction of certain projects in Australia, Japan, and India.
Question:
What are the reasons for the decrease in cash used in investing activities?
Answer: The decrease in net cash used in investing activities during 2019 was primarily due to higher net sales of marketable securities and restricted investments, partially offset by proceeds associated with the sale of our interests in 8point3 and its subsidiaries in 2018.