number of new invisalign doctors trained . we continue to expand our invisalign customer base through the training of new doctors . in 2017 , invisalign growth was driven primarily by increased utilization across all regions as well as by the continued expansion of our customer base as we trained a total of 16,500 new invisalign doctors , of which 67 % were trained internationally . international invisalign growth . we will continue to focus our efforts towards increasing invisalign adoption by dental professionals in our direct international markets . on a year over year basis , international invisalign volume increased 52.3 % driven primarily by strong performance in our apac and emea regions . we believe that the introduction of invisalign teen treatment with mandibular advancement is helping to raise visibility for invisalign treatment of teenagers and contributed to some of the growth in the apac market . in 2018 , we are continuing to expand in our existing markets through targeted investments in sales coverage and professional marketing and education programs , along with consumer marketing in selected country markets . we expect international invisalign clear aligner revenues to continue to grow at a faster rate than north america for the foreseeable future due to our continued investment in international market expansion , the size of the market opportunity , and our relatively low market penetration of these regions ( refer to item 1a risk factors - “ we are exposed to fluctuations in currency exchange rates , which could negatively affect our financial condition and results of operations . ” for information on related risk factors ) . establish regional order acquisition , treatment planning and manufacturing operations . we will continue to establish and expand additional order acquisition , treatment planning and manufacturing operations closer to our international customers in order to improve our operational efficiency and to provide doctors confidence in using invisalign clear aligners to treat more patients and more often : ◦ in june 2017 , we opened a new treatment planning facility in chengdu , china which services and supports our customers within china . it also serves as a clinical education and training center for all of our customers across asia pacific . ◦ in august 2017 , we opened a treatment planning facility in cologne , germany to support our customers located in europe . ◦ in 2017 , we purchased two buildings in costa rica for a total purchase price of approximately $ 51.7 million in order to support our expanding treatment planning and customer service needs . ◦ in november 2017 , we entered into an investment agreement with the people 's republic of china in which we have committed to invest a minimum of $ 46.0 million in ziyang , china over five years to establish manufacturing operations . 36 refer to item 1a risk factors - “ as we continue to grow , we are subject to growth related risks , including risks related to excess or constrained capacity at our existing facilities ” for information on related risk factors and refer to note 9 `` commitments and contingencies `` of the notes of consolidated financial statements for more information on the costa rica purchase agreements and the china investment agreement . operating expenses . we expect operating expenses to increase in 2018 due in part to : ◦ investments in international expansion in new country markets ; ◦ investments in manufacturing to enhance our regional capabilities ; ◦ increases in legal expenses primarily related to the continued protection of our intellectual property rights , including our patents ; ◦ increases in sales , marketing and customer support resources ; and ◦ product and technology innovation to enhance product efficiency and operational productivity . we believe that these investments will position us to increase our revenues and continue to grow our market share . stock repurchases : april 2016 repurchase program . in 2017 , we repurchased $ 50.0 million of our common stock through an accelerated stock repurchase agreement and repurchased $ 50.0 million on the open market . as of december 31 , 2017 , we had $ 200.0 million remaining under the april 2016 repurchase program . in february 2018 , we repurchased $ 100.0 million of our common stock on the open market ( refer to note 11 `` common stock repurchase program `` of the notes to consolidated financial statements for details on stock repurchase program ) . u.s. tax cuts and jobs act . the u.s. tax cuts and jobs act ( the “ tcja ” ) was enacted into law on december 22 , 2017 and impacted our effective tax rate for the year ended december 31 , 2017. the tcja made significant changes to the internal revenue code , including , but not limited to , a corporate tax rate decrease from 35 % to 21 % effective for tax years beginning after december 31 , 2017 , the transition of u.s. international taxation from a worldwide tax system to a territorial system , and a one-time transition tax on the mandatory deemed repatriation of cumulative foreign earnings as of december 31 , 2017. we have estimated the impact of the tcja and recorded a provisional amount of $ 84.3 million additional income tax expense in the fourth quarter of 2017. this provisional amount includes income tax expenses related to the remeasurement of certain deferred tax assets and liabilities of $ 10.4 million , and the one-time transition tax on the mandatory deemed repatriation of cumulative foreign earnings in the amount of $ 73.9 million . additional work is necessary for a more detailed analysis of our deferred tax assets and liabilities and our historical foreign earnings as well as potential correlative adjustments . any subsequent adjustment to these amounts will be recorded to tax expense in 2018 when the analysis is complete . smiledirectclub . story_separator_special_tag our effective tax rate differs from the statutory federal income tax rate of 35 % primarily due to certain foreign earnings , most significantly from the netherlands and costa rica , being taxed at lower tax rates and excess tax benefits related to stock-based compensation recognized as a reduction of income tax expense , partially offset by certain one-time tax charges recorded as a result of the tcja . the increase in the effective tax rate in 2017 compared to 2016 was primarily attributable to tax charges recorded as a result of the tcja and the tax benefit recognized pursuant to the release of valuation allowance against our israel deferred tax assets in 2016 that did not recur this year , partially offset by excess tax benefits related to stock-based compensation recognized as a reduction of income tax expense in accordance with asu 2016-09 and increased tax benefits from foreign earnings being taxed at lower tax rates . the increase in the effective rate for the year ended december 31 , 2016 compared to 2015 was primarily related to our international corporate restructuring as explained below . on july 1 , 2016 , we implemented a new international corporate structure . this changed the structure of our international procurement and sales operations , as well as realigned the ownership and use of intellectual property among our wholly-owned subsidiaries . we continue to anticipate that an increasing percentage of our consolidated pre-tax income will be derived from , and reinvested in our foreign operations . we believe that income taxed in certain foreign jurisdictions at a lower rate relative to the u.s. federal statutory rate will have a beneficial impact on our worldwide effective tax rate over time . although the license of 43 intellectual property rights between consolidated entities did not result in any gain in the consolidated financial statements , the company generated taxable income in certain jurisdictions in 2016 resulting in a tax expense of $ 34.3 million . additionally , as a result of the restructuring , we reassessed the need for a valuation allowance against our deferred tax assets considering all available evidence . given the current earnings and anticipated future earnings of our subsidiary in israel , we concluded that we have sufficient positive evidence to release the valuation allowance against our israel operating loss carryforwards of $ 31.4 million , which resulted in an income tax benefit in 2016. in june 2017 , the costa rica ministry of foreign trade , an agency of the government of costa rica , granted an extension of certain income tax incentives for an additional twelve year period . under these incentives , all of the income in costa rica is subject to a reduced tax rate . in order to receive the benefit of these incentives , we must hire a specified number of employees and maintain certain minimum levels of fixed asset investment in costa rica . if we do not fulfill these conditions for any reason , our incentive could lapse and our income in costa rica would be subject to taxation at higher rates which could have a negative impact on our operating results . the costa rica corporate income tax rate that would apply , absent the incentives , is 30 % for 2017 , 2016 and 2015. as a result of these incentives , our income taxes were reduced by $ 1.8 million , $ 19.1 million and $ 32.7 million in the year ended december 31 , 2017 , 2016 and 2015 respectively , representing a benefit to diluted net income per share of $ 0.02 , $ 0.23 and $ 0.40 in the year ended december 31 , 2017 , 2016 and 2015 , respectively ( refer to note 13 `` income taxes `` of the notes to consolidated financial statements for details on income taxes ) . liquidity and capital resources we fund our operations from product sales . as of december 31 , 2017 and 2016 , we had the following cash and cash equivalents , and short-term and long-term marketable securities ( in thousands ) : replace_table_token_13_th cash flows ( in thousands ) : replace_table_token_14_th as of december 31 , 2017 , we had $ 761.5 million in cash , cash equivalents , and short-term and long-term marketable securities . cash equivalents and marketable securities are comprised of money market funds and highly liquid debt instruments which primarily include commercial paper , corporate bonds , u.s. government agency bonds , u.s. government treasury bonds and certificates of deposit . as of december 31 , 2017 , approximately $ 490.1 million of cash , cash equivalents and short-term and long-term marketable securities was held by our foreign subsidiaries . the tcja enacted into law on december 22 , 2017 included a one-time transition tax on the mandatory deemed repatriation of foreign earnings , and , as a result , we recorded a provisional amount of additional income tax expense of $ 73.9 million , which will be paid over the next eight years . we may repatriate cash and cash equivalents and marketable securities back to the u.s. to invest in market expansion opportunities , provide additional working capital , and have greater flexibility to fund our stock repurchase program ( refer to note 13 `` income taxes `` of the notes to consolidated financial statements for details ) . 44 operating activities for the year ended december 31 , 2017 , cash flows from operations of $ 438.5 million resulted primarily from our net income of approximately $ 231.4 million as well as the following : significant non-cash activities stock-based compensation was $ 58.9 million related to equity incentive compensation granted to employees and directors , depreciation and amortization of $ 37.7 million related to our fixed assets and acquired and purchased intangible assets , and net change in deferred tax assets of $ 17.6 million . significant changes in working capital increase of $ 91.0 million

net cash used in investing activities was $ 248.3 million for the year ended december 31 , 2017 , which primarily consisted of purchases of marketable securities of $ 390.2 million , property , plant and equipment purchases of $ 195.7 million for additional manufacturing capacity and to purchase our new headquarters , $ 30.0 million of loan advances to equity investee , net of repayments and $ 12.8 million related to our equity interest investment in smiledirectclub , llc ( `` sdc '' ) . these outflows were partially offset by maturities and sales of marketable securities of $ 388.8 million . for 2018 , we expect to invest $ 200.0 million to $ 230.0 million on capital expenditures primarily related to operational expansion and ongoing growth of the business . net cash provided by investing activities was $ 72.8 million for the year ended december 31 , 2016 , which primarily consisted of maturities and sales of our marketable securities of $ 604.0 million . these inflows were partially offset by purchases of marketable securities of $ 405.6 million , property , plant and equipment purchases of $ 70.6 million including the implementation of our new erp system and $ 46.7 million related to our equity interest investment in sdc .


 Write a concise suspicious activity report of the following text delimited by triple backquotes. Return your response as a formal report which covers the key points highlighting the location,dates,entity names and account holder information in chronological order of the text.
     ```net cash used in investing activities was $ 248.3 million for the year ended december 31 , 2017 , which primarily consisted of purchases of marketable securities of $ 390.2 million , property , plant and equipment purchases of $ 195.7 million for additional manufacturing capacity and to purchase our new headquarters , $ 30.0 million of loan advances to equity investee , net of repayments and $ 12.8 million related to our equity interest investment in smiledirectclub , llc ( `` sdc '' ) . these outflows were partially offset by maturities and sales of marketable securities of $ 388.8 million . for 2018 , we expect to invest $ 200.0 million to $ 230.0 million on capital expenditures primarily related to operational expansion and ongoing growth of the business . net cash provided by investing activities was $ 72.8 million for the year ended december 31 , 2016 , which primarily consisted of maturities and sales of our marketable securities of $ 604.0 million . these inflows were partially offset by purchases of marketable securities of $ 405.6 million , property , plant and equipment purchases of $ 70.6 million including the implementation of our new erp system and $ 46.7 million related to our equity interest investment in sdc .
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 Suspicious Activity Report : number of new invisalign doctors trained . we continue to expand our invisalign customer base through the training of new doctors . in 2017 , invisalign growth was driven primarily by increased utilization across all regions as well as by the continued expansion of our customer base as we trained a total of 16,500 new invisalign doctors , of which 67 % were trained internationally . international invisalign growth . we will continue to focus our efforts towards increasing invisalign adoption by dental professionals in our direct international markets . on a year over year basis , international invisalign volume increased 52.3 % driven primarily by strong performance in our apac and emea regions . we believe that the introduction of invisalign teen treatment with mandibular advancement is helping to raise visibility for invisalign treatment of teenagers and contributed to some of the growth in the apac market . in 2018 , we are continuing to expand in our existing markets through targeted investments in sales coverage and professional marketing and education programs , along with consumer marketing in selected country markets . we expect international invisalign clear aligner revenues to continue to grow at a faster rate than north america for the foreseeable future due to our continued investment in international market expansion , the size of the market opportunity , and our relatively low market penetration of these regions ( refer to item 1a risk factors - “ we are exposed to fluctuations in currency exchange rates , which could negatively affect our financial condition and results of operations . ” for information on related risk factors ) . establish regional order acquisition , treatment planning and manufacturing operations . we will continue to establish and expand additional order acquisition , treatment planning and manufacturing operations closer to our international customers in order to improve our operational efficiency and to provide doctors confidence in using invisalign clear aligners to treat more patients and more often : ◦ in june 2017 , we opened a new treatment planning facility in chengdu , china which services and supports our customers within china . it also serves as a clinical education and training center for all of our customers across asia pacific . ◦ in august 2017 , we opened a treatment planning facility in cologne , germany to support our customers located in europe . ◦ in 2017 , we purchased two buildings in costa rica for a total purchase price of approximately $ 51.7 million in order to support our expanding treatment planning and customer service needs . ◦ in november 2017 , we entered into an investment agreement with the people 's republic of china in which we have committed to invest a minimum of $ 46.0 million in ziyang , china over five years to establish manufacturing operations . 36 refer to item 1a risk factors - “ as we continue to grow , we are subject to growth related risks , including risks related to excess or constrained capacity at our existing facilities ” for information on related risk factors and refer to note 9 `` commitments and contingencies `` of the notes of consolidated financial statements for more information on the costa rica purchase agreements and the china investment agreement . operating expenses . we expect operating expenses to increase in 2018 due in part to : ◦ investments in international expansion in new country markets ; ◦ investments in manufacturing to enhance our regional capabilities ; ◦ increases in legal expenses primarily related to the continued protection of our intellectual property rights , including our patents ; ◦ increases in sales , marketing and customer support resources ; and ◦ product and technology innovation to enhance product efficiency and operational productivity . we believe that these investments will position us to increase our revenues and continue to grow our market share . stock repurchases : april 2016 repurchase program . in 2017 , we repurchased $ 50.0 million of our common stock through an accelerated stock repurchase agreement and repurchased $ 50.0 million on the open market . as of december 31 , 2017 , we had $ 200.0 million remaining under the april 2016 repurchase program . in february 2018 , we repurchased $ 100.0 million of our common stock on the open market ( refer to note 11 `` common stock repurchase program `` of the notes to consolidated financial statements for details on stock repurchase program ) . u.s. tax cuts and jobs act . the u.s. tax cuts and jobs act ( the “ tcja ” ) was enacted into law on december 22 , 2017 and impacted our effective tax rate for the year ended december 31 , 2017. the tcja made significant changes to the internal revenue code , including , but not limited to , a corporate tax rate decrease from 35 % to 21 % effective for tax years beginning after december 31 , 2017 , the transition of u.s. international taxation from a worldwide tax system to a territorial system , and a one-time transition tax on the mandatory deemed repatriation of cumulative foreign earnings as of december 31 , 2017. we have estimated the impact of the tcja and recorded a provisional amount of $ 84.3 million additional income tax expense in the fourth quarter of 2017. this provisional amount includes income tax expenses related to the remeasurement of certain deferred tax assets and liabilities of $ 10.4 million , and the one-time transition tax on the mandatory deemed repatriation of cumulative foreign earnings in the amount of $ 73.9 million . additional work is necessary for a more detailed analysis of our deferred tax assets and liabilities and our historical foreign earnings as well as potential correlative adjustments . any subsequent adjustment to these amounts will be recorded to tax expense in 2018 when the analysis is complete . smiledirectclub . story_separator_special_tag our effective tax rate differs from the statutory federal income tax rate of 35 % primarily due to certain foreign earnings , most significantly from the netherlands and costa rica , being taxed at lower tax rates and excess tax benefits related to stock-based compensation recognized as a reduction of income tax expense , partially offset by certain one-time tax charges recorded as a result of the tcja . the increase in the effective tax rate in 2017 compared to 2016 was primarily attributable to tax charges recorded as a result of the tcja and the tax benefit recognized pursuant to the release of valuation allowance against our israel deferred tax assets in 2016 that did not recur this year , partially offset by excess tax benefits related to stock-based compensation recognized as a reduction of income tax expense in accordance with asu 2016-09 and increased tax benefits from foreign earnings being taxed at lower tax rates . the increase in the effective rate for the year ended december 31 , 2016 compared to 2015 was primarily related to our international corporate restructuring as explained below . on july 1 , 2016 , we implemented a new international corporate structure . this changed the structure of our international procurement and sales operations , as well as realigned the ownership and use of intellectual property among our wholly-owned subsidiaries . we continue to anticipate that an increasing percentage of our consolidated pre-tax income will be derived from , and reinvested in our foreign operations . we believe that income taxed in certain foreign jurisdictions at a lower rate relative to the u.s. federal statutory rate will have a beneficial impact on our worldwide effective tax rate over time . although the license of 43 intellectual property rights between consolidated entities did not result in any gain in the consolidated financial statements , the company generated taxable income in certain jurisdictions in 2016 resulting in a tax expense of $ 34.3 million . additionally , as a result of the restructuring , we reassessed the need for a valuation allowance against our deferred tax assets considering all available evidence . given the current earnings and anticipated future earnings of our subsidiary in israel , we concluded that we have sufficient positive evidence to release the valuation allowance against our israel operating loss carryforwards of $ 31.4 million , which resulted in an income tax benefit in 2016. in june 2017 , the costa rica ministry of foreign trade , an agency of the government of costa rica , granted an extension of certain income tax incentives for an additional twelve year period . under these incentives , all of the income in costa rica is subject to a reduced tax rate . in order to receive the benefit of these incentives , we must hire a specified number of employees and maintain certain minimum levels of fixed asset investment in costa rica . if we do not fulfill these conditions for any reason , our incentive could lapse and our income in costa rica would be subject to taxation at higher rates which could have a negative impact on our operating results . the costa rica corporate income tax rate that would apply , absent the incentives , is 30 % for 2017 , 2016 and 2015. as a result of these incentives , our income taxes were reduced by $ 1.8 million , $ 19.1 million and $ 32.7 million in the year ended december 31 , 2017 , 2016 and 2015 respectively , representing a benefit to diluted net income per share of $ 0.02 , $ 0.23 and $ 0.40 in the year ended december 31 , 2017 , 2016 and 2015 , respectively ( refer to note 13 `` income taxes `` of the notes to consolidated financial statements for details on income taxes ) . liquidity and capital resources we fund our operations from product sales . as of december 31 , 2017 and 2016 , we had the following cash and cash equivalents , and short-term and long-term marketable securities ( in thousands ) : replace_table_token_13_th cash flows ( in thousands ) : replace_table_token_14_th as of december 31 , 2017 , we had $ 761.5 million in cash , cash equivalents , and short-term and long-term marketable securities . cash equivalents and marketable securities are comprised of money market funds and highly liquid debt instruments which primarily include commercial paper , corporate bonds , u.s. government agency bonds , u.s. government treasury bonds and certificates of deposit . as of december 31 , 2017 , approximately $ 490.1 million of cash , cash equivalents and short-term and long-term marketable securities was held by our foreign subsidiaries . the tcja enacted into law on december 22 , 2017 included a one-time transition tax on the mandatory deemed repatriation of foreign earnings , and , as a result , we recorded a provisional amount of additional income tax expense of $ 73.9 million , which will be paid over the next eight years . we may repatriate cash and cash equivalents and marketable securities back to the u.s. to invest in market expansion opportunities , provide additional working capital , and have greater flexibility to fund our stock repurchase program ( refer to note 13 `` income taxes `` of the notes to consolidated financial statements for details ) . 44 operating activities for the year ended december 31 , 2017 , cash flows from operations of $ 438.5 million resulted primarily from our net income of approximately $ 231.4 million as well as the following : significant non-cash activities stock-based compensation was $ 58.9 million related to equity incentive compensation granted to employees and directors , depreciation and amortization of $ 37.7 million related to our fixed assets and acquired and purchased intangible assets , and net change in deferred tax assets of $ 17.6 million . significant changes in working capital increase of $ 91.0 million

