text: Item 6. Selected Financial Data
text: The following tables set forth our selected financial data for the periods and at the dates indicated. The selected financial data from the consolidated statements of operations and consolidated statements of cash flows for the years ended December 31, 2019, 2018, and 2017 and the selected financial data from the consolidated balance sheets as of December 31, 2019 and 2018 have been derived from the audited consolidated financial statements included in this Annual Report on Form 10-K. The selected financial data from the consolidated statements of operations and consolidated statements of cash flows for the years ended December 31, 2016 and 2015 and the selected financial data from the consolidated balance sheets as of December 31, 2017, 2016, and 2015 have been derived from audited consolidated financial statements not included in this Annual Report on Form 10-K. The information presented below should also be read in conjunction with our consolidated financial statements and the related notes thereto and Item 7. “Management’s Discussion and Analysis of Financial Condition and Results of Operations.”

Table:
Years Ended December 31,
2019
2018
2017
2016
2015
(In thousands, except per share amounts)
Net sales .
$3,063,117
$2,244,044
$2,941,324
$2,904,563
$4,112,650
Gross profit
549,212
392,177
548,947
638,418
1,132,762
Operating (loss) income .
(161,785)
40,113
177,851
(568,151)
730,159
Net (loss) income
(114,933)
144,326
(165,615)
(416,112)
593,406
Net (loss) income per share:
Basic .
$(1.09)
$1.38
$(1.59)
$(4.05)
$5.88
Diluted .
$(1.09)
$1.36
$(1.59)
$(4.05)
$5.83
Cash dividends declared per common share.
$—
$—
$—
$—
$—
Net cash provided by (used in) operating
activities
$174,201
$(326,809)
$1,340,677
$206,753
$(325,209)
Net cash (used in) provided by investing
activities
(362,298)
(682,714)
(626,802)
144,520
(156,177)
Net cash provided by (used in) financing
activities
74,943
255,228
192,045
(136,393)
101,207
December 31,
2019
2018
2017
2016
2015
(In thousands)
Cash and cash equivalents .
$1,352,741
$1,403,562
$2,268,534
$1,347,155
$1,126,826
Marketable securities .
811,506
1,143,704
720,379
607,991
703,454
Total assets .
7,515,689
7,121,362
6,864,501
6,824,368
7,360,392
Total long-term debt
471,697
466,791
393,540
188,388
289,415
Total liabilities
2,418,922
1,908,959
1,765,804
1,606,019
1,741,996
Total stockholders’ equity .
5,096,767
5,212,403
5,098,697
5,218,349
5,618,396

Questions:
question: What was the net income per basic share in 2018?
answer: $1.38
question: What was the net cash provided by (used in) operating activities in 2018 and 2019 respectively?
answer: $(326,809)
$174,201
scale: thousand
question: What was the amount of marketable securities in 2019?
answer: 811,506
scale: thousand
question: What is the change in total shareholders' equity from 2018 to 2019?
answer: -2.22
derivation: (5,096,767 - 5,212,403) / 5,212,403 
scale: percent
question: What is the difference between Net (loss) income in 2018 and 2019?
answer: 259259
derivation: 144,326 - (-114,933) 
scale: thousand
question: What was the percentage increase in gross profit from 2018 to 2019?
answer: 40.04
derivation: (549,212 - 392,177) / 392,177 
scale: percent