Cash Flows
The following table sets forth summary cash flow data for the periods indicated (in thousands).
Cash Flow from Operating Activities
Net cash flows provided by operating activities for the year ended December 31, 2019, were $137.6 million as compared to $183.9 million during the same period in 2018. Net cash provided by operating activities primarily consists of net income adjusted to add back depreciation, amortization, and stock-based compensation. Cash flows provided by operating activities were $46.3 million lower for the year ended December 31, 2019, compared to the same period in 2018, due to the timing of working capital. Our current policy is to use our operating cash flow primarily for funding capital expenditures, lease payments, stock repurchases, and acquisitions.
Cash Flow from Investing Activities
During the year ended December 31, 2019, we paid $753.9 million, net of $0.1 million in cash acquired, to acquire Speedpay. We also used cash of $18.5 million to invest in a payment technology and services company in India and $7.0 million to acquire the technology assets of RevChip, LLC and TranSend Integrated Technologies Inc. In addition, we used cash of $48.0 million to purchase software, property and equipment, as compared to $43.9 million during the same period in 2018.
Cash Flow from Financing Activities
Net cash flows provided by financing activities for the year ended December 31, 2019, were $667.2 million, as compared to net cash flows used by financing activities of $57.7 million during the same period in 2018. During 2019, we received proceeds of $500.0 million from our Delayed Draw Term Loan and $280.0 million from our Revolving Credit Facility to fund our purchase of Speedpay and stock repurchases, and we repaid $28.9 million on the Initial Term Loan and $41.0 million on the Revolving Credit Facility. In addition, we received proceeds of $16.6 million from the exercise of stock options and the issuance of common stock under our 2017 Employee Stock Purchase Plan, as amended, and used $4.0 million for the repurchase of stock-based compensation awards for tax withholdings. During 2019, we also used $35.6 million to repurchase common stock. During 2018, we received proceeds of $400.0 million from the issuance of the 2026 Notes. We used $300.0 million of the proceeds to redeem, in full, our outstanding 6.375% Senior Notes due 2020 and repaid $109.3 million on the Initial Term Loan. In addition, during 2018, we received proceeds of $22.8 million from the exercise of stock options and the issuance of common stock under our 2017 Employee Stock Purchase Plan, as amended, and used $2.6 million for the repurchase of restricted share awards ("RSAs") for tax withholdings. During 2018, we also used $54.5 million to repurchase common stock.

Years Ended December 31,
2019
2018
Net cash provided by (used in):
Operating activities
$137,649
$183,932
Investing activities
-830,481
-45,360
Financing activities
667,223
-57,704


Question: Analyse this data from a financial earnings document. What was the change in net cash used in investing activities between 2018 and 2019?
Choices:
-772777
-875841
-785121
90720
-7851
Correct choice index: 2