factors that could cause or contribute to such differences include , but are not limited to , those discussed in the “ risk factors ” section of this annual report on form 10-k overview we are a clinical stage biopharmaceutical company pioneering a novel disease-modifying therapeutic approach to treat what we believe to be a key underlying cause of alzheimer 's and other degenerative diseases . our approach is based on the seminal discovery of the presence of porphyromonas gingivalis , or p. gingivalis , and its secreted toxic virulence factor proteases , called gingipains , in the brains of greater than 90 % of more than 100 alzheimer 's patients observed across multiple studies to date . additionally , we have observed that p. gingivalis infection causes alzheimer 's pathology in animal models , and these effects have been successfully treated with a gingipain inhibitor in preclinical studies . our proprietary lead drug candidate , cor388 , is an orally administered , brain-penetrating small molecule gingipain inhibitor . cor388 was well-tolerated with no concerning safety signals in our phase 1a and phase 1b clinical trials conducted to date , which enrolled a total of 67 subjects , including nine patients with mild to moderate alzheimer 's disease . we initiated a global phase 2/3 clinical trial of cor388 , called the gain trial , in mild to moderate alzheimer 's patients in april 2019 in the united states and in september 2019 in europe and expect top-line results by the end of 2021. financial overview since commencing material operations in 2014 , we have devoted substantially all of our efforts and financial resources to building our research and development capabilities , establishing our corporate infrastructure and most recently , executing our phase 1a , phase 1b and phase 2/3 clinical trials of cor388 . to date , we have not generated any revenue and we have never been profitable . we have incurred net losses since the commencement of our operations . as of december 31 , 2019 , we had an accumulated deficit of $ 69.8 million . we incurred a net loss of $ 37.0 million in the year ended december 31 , 2019. we do not expect to generate product revenue unless and until we obtain marketing approval for and commercialize a drug candidate , and we can not assure you that we will ever generate significant revenue or profits . to date , we have financed our operations primarily through the issuance and sale of convertible promissory notes and redeemable convertible preferred stock and common stock . from inception through december 31 , 2019 , we received net proceeds of approximately $ 177.3 million from the issuance of redeemable convertible preferred stock , convertible promissory notes and common stock . in february 2020 , we also received net proceeds of approximately $ 117.6 million from the issuance and sale of common stock in a private placement to certain accredited investors as of december 31 , 2019 and 2018 , we had cash , cash equivalents and short-term investments of $ 99.9 million and $ 71.7 million , respectively . the balances exclude long-term investments of $ 16.8 million and $ 0 as of those same periods . our cash equivalents , short-term and long-term investments are held in money market funds , certificate of deposits , repurchase agreements , investments in corporate debt securities and government agency obligations . we believe that our existing cash , cash equivalents and short-term investments will be sufficient to fund our planned operations through 2021 , including through the completion and the announcement of the top-line results of our phase 2/3 gain trial . we have based this estimate on assumptions that may prove to be wrong , and we could utilize our available capital resources sooner than we expect . we expect to incur substantial expenditures in the foreseeable future as we expand our pipeline and advance our drug candidates through clinical development , the regulatory approval process and , if approved , commercial launch activities . specifically , in the near term we expect to incur substantial expenses relating to our ongoing and planned clinical trials , the development and validation of our manufacturing processes , and other development activities . 59 we will need substantial additional funding to support our continuing operations and pursue our development strategy . until such time as we can generate significant revenue from sales of an approved drug , if ever , we expect to finance our operations through the sale of equity , debt financings or other capital sources . adequate funding may not be available to us on acceptable terms , or at all . if we fail to raise capital or enter into such agreements as , and when , needed , we may have to significantly delay , scale back or discontinue the development and commercialization of our drug candidates or delay our efforts to expand our product pipeline . components of operating results operating expenses research and development expenses our research and development expenses consist of expenses incurred in connection with the research and development of our research programs . these expenses include payroll and personnel expenses , including stock-based compensation , for our research and product development employees , laboratory supplies , product licenses , consulting costs , contract research , preclinical and clinical expenses , allocated rent , facilities costs and depreciation . we expense both internal and external research and development costs as they are incurred . non-refundable advance payments and deposits for services that will be used or rendered for future research and development activities are recorded as prepaid expenses and recognized as an expense as the related services are performed . story_separator_special_tag our research and development activities ; the costs associated with securing and establishing commercialization and manufacturing capabilities ; the costs of acquiring , licensing or investing in businesses , drug candidates and technologies ; our ability to maintain , expand and defend the scope of our intellectual property portfolio , including the amount and timing of any payments we may be required to make , or that we may receive , in connection with the licensing , filing , prosecution , defense and enforcement of any patents or other intellectual property rights ; our need and ability to retain management and hire scientific and clinical personnel ; the effect of competing drugs and drug candidates and other market developments ; our need to implement additional internal systems and infrastructure , including financial and reporting systems ; and the economic and other terms , timing of and success of any collaboration , licensing or other arrangements into which we may enter in the future . if we raise additional funds by issuing equity securities , our stockholders will experience dilution . any future debt financing into which we enter may impose upon us additional covenants that restrict our operations , including limitations on our ability to incur liens or additional debt , pay dividends , repurchase our common stock , make certain investments and engage in certain merger , consolidation or asset sale transactions . any debt financing or additional equity that we raise may contain terms that are not favorable to us or our stockholders . if we are unable to raise additional funds when needed , we may be required to delay , reduce , or terminate some or all of our development programs and clinical trials . we may also be required to sell or license to others rights to our drug candidates in certain territories or indications that we would prefer to develop and commercialize ourselves . 64 summary statement of cash flows the following table sets forth the primary sources and uses of cash and cash equivalents for each of the periods presented below ( in thousands ) : replace_table_token_3_th story_separator_special_tag disclosure framework project . the disclosure framework project aims to improve the effectiveness of disclosures in the notes to the financial statements by focusing on requirements that clearly communicate the most important information to users of the financial statements . this guidance is effective for fiscal years beginning after december 15 , 2019 , with early adoption permitted . the company does not believe this pronouncement will have a material impact on its financial statements or disclosures . in june 2016 , the fasb issued asu no . 2016-13 , financial instruments – credit losses ( topic 326 ) : measurement of credit losses on financial instruments ( “ asu 2016-13 ” ) . asu 2016-13 requires companies to measure credit losses utilizing a methodology that reflects expected credit losses and requires a consideration of a broader range of reasonable and supportable information to inform credit loss estimates . asu 2016-13 is effective for public business entities that are sec filers , excluding smaller reporting companies for fiscal years beginning after december 15 , 2019 , including interim periods within those fiscal years . all other entities , including smaller reporting companies the effective date is for fiscal years beginning after december 15 , 2022. accordingly , as a smaller reporting company , we will adopt the standard effective january 1 , 2023. we are currently evaluating the impact that the adoption of this standard will have on our financial statements . in august 2018 , the fasb issued asu no . 2018-15 , intangibles—goodwill and other—internal-use software ( subtopic 350-40 ) : customer 's accounting for implementation costs incurred in a cloud computing arrangement that is a service contract ( “ asu 2018-15 ” ) , which clarifies the accounting for implementation costs in cloud computing arrangements . asu 2018-15 is effective for fiscal years beginning after december 15 , 2019 , including interim periods within those fiscal years . we will adopt the standard prospectively on january 1 , 2020. we do not expect the adoption of asu 2018-15 to result in a material change to our financial statements . 66 recently adopted accounting pronouncements in february 2016 , the fasb issued asu no . 2016-02 , leases ( topic 842 ) . this asu requires that substantially all leases be recognized by lessees on their balance sheet as a right-of-use asset and corresponding lease liability , including leases currently accounted for as operating leases . the asu is effective for interim and annual periods beginning after december 15 , 2018. additionally , the fasb issued asu no . 2018-11 , leases ( topic 842 ) : targeted improvements , which offers an additional transition method whereby entities may apply the new leases standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings rather than application of the new leases standard at the beginning of the earliest period presented in the financial statements . the company elected this transition method and adopted asc 842 on january 1 , 2019 and as a result , recorded a right-of-use asset of $ 0.9 million , a short-term lease liability of $ 0.3 million , and a long-term lease liability of $ 0.6 million and no cumulative effect adjustment was made to the retained earnings as of the adoption date . the company also elected the package of practical expedients under the transition guidance that will retain the historical lease classification and initial direct costs for any leases that exist prior to adoption of the new guidance and the practical expedient to not separate lease and nonlease components . see note 6 to our audited financial statements for further information . in july 2017 , the fasb issued asu no . 2017-11 , earnings per share ( topic 260 ) , distinguishing liabilities from equity ( topic 480 )

cash used in operating activities net cash used in operating activities was $ 33.3 million for the year ended december 31 , 2019 and $ 11.7 million for the year ended december 31 , 2018. cash used in operating activities in the year ended december 31 , 2019 was primarily due to our net loss for the period of $ 37.0 million , which included non-cash expenses of $ 2.6 million and changes to operating assets and liabilities of $ 1.9 million offset by non-cash interest income of $ 0.8 million . cash used in operating activities in the year ended december 31 , 2018 was primarily due to our net loss for the period of $ 12.5 million , and was also affected by changes to accrued interest , debt discount on conversion features , operating assets and liabilities , other current assets and long-term assets that totaled $ 1.5 million . cash used in operating activities was also affected by changes in operating assets and liabilities , a decrease in prepaids of $ 0.7 million and increase in accrued liabilities of $ 0.3 million , and non-cash charges relating to depreciation and amortization and stock-based compensation expense of $ 0.1 million . cash used in investing activities cash used in investing activities was $ 17.7 million in the year ended december 31 , 2019 , primarily related to the purchase of investments of $ 135.4 million and maturities of debt investments of $ 117.7 million .


 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.
     ```cash used in operating activities net cash used in operating activities was $ 33.3 million for the year ended december 31 , 2019 and $ 11.7 million for the year ended december 31 , 2018. cash used in operating activities in the year ended december 31 , 2019 was primarily due to our net loss for the period of $ 37.0 million , which included non-cash expenses of $ 2.6 million and changes to operating assets and liabilities of $ 1.9 million offset by non-cash interest income of $ 0.8 million . cash used in operating activities in the year ended december 31 , 2018 was primarily due to our net loss for the period of $ 12.5 million , and was also affected by changes to accrued interest , debt discount on conversion features , operating assets and liabilities , other current assets and long-term assets that totaled $ 1.5 million . cash used in operating activities was also affected by changes in operating assets and liabilities , a decrease in prepaids of $ 0.7 million and increase in accrued liabilities of $ 0.3 million , and non-cash charges relating to depreciation and amortization and stock-based compensation expense of $ 0.1 million . cash used in investing activities cash used in investing activities was $ 17.7 million in the year ended december 31 , 2019 , primarily related to the purchase of investments of $ 135.4 million and maturities of debt investments of $ 117.7 million .
```    
 Suspicious Activity Report : factors that could cause or contribute to such differences include , but are not limited to , those discussed in the “ risk factors ” section of this annual report on form 10-k overview we are a clinical stage biopharmaceutical company pioneering a novel disease-modifying therapeutic approach to treat what we believe to be a key underlying cause of alzheimer 's and other degenerative diseases . our approach is based on the seminal discovery of the presence of porphyromonas gingivalis , or p. gingivalis , and its secreted toxic virulence factor proteases , called gingipains , in the brains of greater than 90 % of more than 100 alzheimer 's patients observed across multiple studies to date . additionally , we have observed that p. gingivalis infection causes alzheimer 's pathology in animal models , and these effects have been successfully treated with a gingipain inhibitor in preclinical studies . our proprietary lead drug candidate , cor388 , is an orally administered , brain-penetrating small molecule gingipain inhibitor . cor388 was well-tolerated with no concerning safety signals in our phase 1a and phase 1b clinical trials conducted to date , which enrolled a total of 67 subjects , including nine patients with mild to moderate alzheimer 's disease . we initiated a global phase 2/3 clinical trial of cor388 , called the gain trial , in mild to moderate alzheimer 's patients in april 2019 in the united states and in september 2019 in europe and expect top-line results by the end of 2021. financial overview since commencing material operations in 2014 , we have devoted substantially all of our efforts and financial resources to building our research and development capabilities , establishing our corporate infrastructure and most recently , executing our phase 1a , phase 1b and phase 2/3 clinical trials of cor388 . to date , we have not generated any revenue and we have never been profitable . we have incurred net losses since the commencement of our operations . as of december 31 , 2019 , we had an accumulated deficit of $ 69.8 million . we incurred a net loss of $ 37.0 million in the year ended december 31 , 2019. we do not expect to generate product revenue unless and until we obtain marketing approval for and commercialize a drug candidate , and we can not assure you that we will ever generate significant revenue or profits . to date , we have financed our operations primarily through the issuance and sale of convertible promissory notes and redeemable convertible preferred stock and common stock . from inception through december 31 , 2019 , we received net proceeds of approximately $ 177.3 million from the issuance of redeemable convertible preferred stock , convertible promissory notes and common stock . in february 2020 , we also received net proceeds of approximately $ 117.6 million from the issuance and sale of common stock in a private placement to certain accredited investors as of december 31 , 2019 and 2018 , we had cash , cash equivalents and short-term investments of $ 99.9 million and $ 71.7 million , respectively . the balances exclude long-term investments of $ 16.8 million and $ 0 as of those same periods . our cash equivalents , short-term and long-term investments are held in money market funds , certificate of deposits , repurchase agreements , investments in corporate debt securities and government agency obligations . we believe that our existing cash , cash equivalents and short-term investments will be sufficient to fund our planned operations through 2021 , including through the completion and the announcement of the top-line results of our phase 2/3 gain trial . we have based this estimate on assumptions that may prove to be wrong , and we could utilize our available capital resources sooner than we expect . we expect to incur substantial expenditures in the foreseeable future as we expand our pipeline and advance our drug candidates through clinical development , the regulatory approval process and , if approved , commercial launch activities . specifically , in the near term we expect to incur substantial expenses relating to our ongoing and planned clinical trials , the development and validation of our manufacturing processes , and other development activities . 59 we will need substantial additional funding to support our continuing operations and pursue our development strategy . until such time as we can generate significant revenue from sales of an approved drug , if ever , we expect to finance our operations through the sale of equity , debt financings or other capital sources . adequate funding may not be available to us on acceptable terms , or at all . if we fail to raise capital or enter into such agreements as , and when , needed , we may have to significantly delay , scale back or discontinue the development and commercialization of our drug candidates or delay our efforts to expand our product pipeline . components of operating results operating expenses research and development expenses our research and development expenses consist of expenses incurred in connection with the research and development of our research programs . these expenses include payroll and personnel expenses , including stock-based compensation , for our research and product development employees , laboratory supplies , product licenses , consulting costs , contract research , preclinical and clinical expenses , allocated rent , facilities costs and depreciation . we expense both internal and external research and development costs as they are incurred . non-refundable advance payments and deposits for services that will be used or rendered for future research and development activities are recorded as prepaid expenses and recognized as an expense as the related services are performed . story_separator_special_tag our research and development activities ; the costs associated with securing and establishing commercialization and manufacturing capabilities ; the costs of acquiring , licensing or investing in businesses , drug candidates and technologies ; our ability to maintain , expand and defend the scope of our intellectual property portfolio , including the amount and timing of any payments we may be required to make , or that we may receive , in connection with the licensing , filing , prosecution , defense and enforcement of any patents or other intellectual property rights ; our need and ability to retain management and hire scientific and clinical personnel ; the effect of competing drugs and drug candidates and other market developments ; our need to implement additional internal systems and infrastructure , including financial and reporting systems ; and the economic and other terms , timing of and success of any collaboration , licensing or other arrangements into which we may enter in the future . if we raise additional funds by issuing equity securities , our stockholders will experience dilution . any future debt financing into which we enter may impose upon us additional covenants that restrict our operations , including limitations on our ability to incur liens or additional debt , pay dividends , repurchase our common stock , make certain investments and engage in certain merger , consolidation or asset sale transactions . any debt financing or additional equity that we raise may contain terms that are not favorable to us or our stockholders . if we are unable to raise additional funds when needed , we may be required to delay , reduce , or terminate some or all of our development programs and clinical trials . we may also be required to sell or license to others rights to our drug candidates in certain territories or indications that we would prefer to develop and commercialize ourselves . 64 summary statement of cash flows the following table sets forth the primary sources and uses of cash and cash equivalents for each of the periods presented below ( in thousands ) : replace_table_token_3_th story_separator_special_tag disclosure framework project . the disclosure framework project aims to improve the effectiveness of disclosures in the notes to the financial statements by focusing on requirements that clearly communicate the most important information to users of the financial statements . this guidance is effective for fiscal years beginning after december 15 , 2019 , with early adoption permitted . the company does not believe this pronouncement will have a material impact on its financial statements or disclosures . in june 2016 , the fasb issued asu no . 2016-13 , financial instruments – credit losses ( topic 326 ) : measurement of credit losses on financial instruments ( “ asu 2016-13 ” ) . asu 2016-13 requires companies to measure credit losses utilizing a methodology that reflects expected credit losses and requires a consideration of a broader range of reasonable and supportable information to inform credit loss estimates . asu 2016-13 is effective for public business entities that are sec filers , excluding smaller reporting companies for fiscal years beginning after december 15 , 2019 , including interim periods within those fiscal years . all other entities , including smaller reporting companies the effective date is for fiscal years beginning after december 15 , 2022. accordingly , as a smaller reporting company , we will adopt the standard effective january 1 , 2023. we are currently evaluating the impact that the adoption of this standard will have on our financial statements . in august 2018 , the fasb issued asu no . 2018-15 , intangibles—goodwill and other—internal-use software ( subtopic 350-40 ) : customer 's accounting for implementation costs incurred in a cloud computing arrangement that is a service contract ( “ asu 2018-15 ” ) , which clarifies the accounting for implementation costs in cloud computing arrangements . asu 2018-15 is effective for fiscal years beginning after december 15 , 2019 , including interim periods within those fiscal years . we will adopt the standard prospectively on january 1 , 2020. we do not expect the adoption of asu 2018-15 to result in a material change to our financial statements . 66 recently adopted accounting pronouncements in february 2016 , the fasb issued asu no . 2016-02 , leases ( topic 842 ) . this asu requires that substantially all leases be recognized by lessees on their balance sheet as a right-of-use asset and corresponding lease liability , including leases currently accounted for as operating leases . the asu is effective for interim and annual periods beginning after december 15 , 2018. additionally , the fasb issued asu no . 2018-11 , leases ( topic 842 ) : targeted improvements , which offers an additional transition method whereby entities may apply the new leases standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings rather than application of the new leases standard at the beginning of the earliest period presented in the financial statements . the company elected this transition method and adopted asc 842 on january 1 , 2019 and as a result , recorded a right-of-use asset of $ 0.9 million , a short-term lease liability of $ 0.3 million , and a long-term lease liability of $ 0.6 million and no cumulative effect adjustment was made to the retained earnings as of the adoption date . the company also elected the package of practical expedients under the transition guidance that will retain the historical lease classification and initial direct costs for any leases that exist prior to adoption of the new guidance and the practical expedient to not separate lease and nonlease components . see note 6 to our audited financial statements for further information . in july 2017 , the fasb issued asu no . 2017-11 , earnings per share ( topic 260 ) , distinguishing liabilities from equity ( topic 480 )

