Years ended December 31,
Years ended December 31,
2019
2018
Net cash provided by/(used in) operating activities
$4,798,201
$(3,308,826)
Net cash (used in)/provided by investing activities
(19,814,991)
10,037,123
Net cash used in financing activities
(2,437,560)
(1,249,564)
Net (decrease)/increase in cash and cash equivalents
$(17,454,350)
$5,478,733
discussion of cash flows .
during 2019 the $ 4 .
8 million of net cash provided by operating activities consisted of our net income of $ 5 .
3 million and included non-cash charges for depreciation and amortization of $ 2 .
5 million and stock-based compensation of $ 1 .
5 million offset by a tax benefit from a partial release of the valuation allowances of $ 3 .
3 million and a net cash outflow of $ 1 .
8 million from changes in working capital .
the changes in working capital were principally driven by an increase in accounts receivable of $ 2 .
2 million an increase in inventory of $ 0 .
7 million an increase in contract assets of $ 0 .
4 million and an increase in other assets of $ 0 .
2 million all partially offset by decreases in accounts payable and accrued expenses of $ 0 .
6 million and contract liabilities of $ 1 .
2 million .
in 2018 the $ 3 .
3 million of net cash used in operating activities consisted of our net income of $ 11 .
0 million and included a gain recognized on the sale of our optoelectronic segment that was sold in july 2018 of $ 8 .
6 million in addition to non-cash charges for depreciation and amortization of $ 1 .
2 million and stock-based compensation of $ 0 .
6 million offset by a net cash outflow of $ 7 .
6 million from changes in working capital .
the changes in working capital were principally driven by an increase in inventory of $ 1 .
0 million and increase in accounts receivable of $ 6 .
2 million and increase in contract assets of $ 0 .
8 million and an increase in accounts payable and accrued liabilities of $ 0 .
5 million all partially offset by a $ 1 .
8 million decrease in other assets .
cash used in investing activities in 2019 consisted primarily of the $ 19 .
0 million payment for our acquisition of gp $ 0 .
5 million of fixed asset additions and $ 0 .
3 million of capitalized intellectual property costs .
cash provided by investing activities in 2018 consisted primarily of the proceeds from the sale of our optoelectronic segment of $ 15 .
8 million partially offset by the $ 5 .
0 million payment for our acquisition of moi $ 0 .
4 million of fixed asset additions and $ 0 .
4 million of capitalized intellectual property rights .
cash used in financing activities for the year ended december 31 2019 was $ 2 .
4 million compared to $ 1 .
2 million in 2018 .
during 2019 we repaid $ 0 .
6 million on our term loans with svb and used $ 2 .
2 million to repurchase our common stock under our stock repurchase program .
these payments were partially offset by $ 0 .
4 million received from exercises of stock options and warrants .
during 2018 we repaid $ 1 .
8 million on our outstanding term loan with svb and used $ 0 .
5 million to repurchase our common stock under our stock repurchase program .
these payments were partially offset by $ 1 .
1 million received from exercises of stock options and warrants .

Question: In which year was Net cash provided by/(used in) operating activities negative?
Answer: 2018