product revenue will depend on our ability to receive regulatory approvals for , and successfully market , our drug candidates . we have yet to generate any revenues from product sales and have recorded an accumulated deficit of $ 699.7 million at december 31 , 2015. these losses have resulted principally from costs incurred in connection with research and development activities , compensation and other related personnel costs and general corporate expenses . research and development activities include costs of outside contracted services including clinical trial costs , manufacturing and process development costs , research costs and other consulting services . salaries and other personnel-related costs include non-cash stock-based compensation associated with options and other equity awards granted to employees . general corporate expenses include outside services such as accounting , consulting , business development , commercial , investor relations , insurance services and legal costs . our operating results may fluctuate substantially from period to period principally as a result of the timing of preclinical activities and other activities related to clinical trials for our drug candidates . since our inception , we have relied primarily on the proceeds from public and private sales of our equity securities , government grants and revenues from collaboration agreements to fund our operations . we expect to continue to spend substantial funds in connection with the development and manufacturing of our product candidates , particularly heplisav-b and our investigational cancer immunotherapeutic product candidate , sd-101 , human clinical trials for our other product candidates and additional applications and advancement of our technology . costs relating to hbv-23 declined following the last subject visit in october 2015 , but costs relating to seeking regulatory approval and preparing for the anticipated commercial launch of heplisav-b in the united states , as well as costs related to the ongoing development of sd-101 and our other cancer immunotherapeutic research and development programs , are increasing . in order to continue these activities , we may need to raise additional funds . this may occur through strategic alliance and licensing arrangements and or future public or private debt and equity financings . if adequate funds are not available in the future , we may need to delay , reduce the scope of or put on hold the heplisav-b program or other development programs while we seek strategic alternatives . 29 critical accounting policies and the use of estimates the accompanying discussion and analysis of our financial condition and results of operations are based upon our consolidated financial statements and the related disclosures , which have been prepared in accordance with u.s. generally accepted accounting principles . the preparation of these financial statements requires us to make estimates , assumptions and judgments that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the balance sheet dates and the reported amounts of revenues and expenses for the periods presented . on an ongoing basis , we evaluate our estimates , assumptions and judgments described below that have the greatest potential impact on our consolidated financial statements , including those related to revenue recognition , research and development activities and stock-based compensation . we base our estimates on historical experience and on various other assumptions that we believe to be reasonable under the circumstances , the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources . accounting assumptions and estimates are inherently uncertain and actual results may differ materially from these estimates under different assumptions or conditions . while our significant accounting policies are more fully described in note 2 to the consolidated financial statements , we believe the following critical accounting policies reflect the more significant judgments and estimates used in the preparation of our financial statements . revenue recognition our revenues consist of amounts earned from collaborations , grants and fees from services and licenses . we enter into license and manufacturing agreements and collaborative research and development arrangements with pharmaceutical and biotechnology partners that may involve multiple deliverables . our arrangements may include one or more of the following elements : upfront license payments , cost reimbursement for the performance of research and development activities , milestone payments , other contingent payments , contract manufacturing service fees , royalties and license fees . each deliverable in the arrangement is evaluated to determine whether it meets the criteria to be accounted for as a separate unit of accounting or whether it should be combined with other deliverables . in order to account for the multiple-element arrangements , the company identifies the deliverables included within the arrangement and evaluates which deliverables represent separate units of accounting . analyzing the arrangement to identify deliverables requires the use of judgment , and each deliverable may be an obligation to deliver services , a right or license to use an asset , or another performance obligation . we recognize revenue when there is persuasive evidence that an arrangement exists , delivery has occurred or services have been rendered , the price is fixed or determinable and collectability is reasonably assured . non-refundable upfront fees received for license and collaborative agreements entered into prior to january 1 , 2011 and other payments under collaboration agreements where we have continuing performance obligations related to the payments are deferred and recognized over our estimated performance period . revenue is recognized on a ratable basis , unless we determine that another method is more appropriate , through the date at which our performance obligations are completed . management makes its best estimate of the period over which we expect to fulfill our performance obligations , which may include clinical development activities . given the uncertainties of research and development collaborations , significant judgment is required to determine the duration of the performance period . story_separator_special_tag the following is a summary of our interest income and expense , other income , and loss on extinguishment of debt ( in thousands , except for percentages ) : replace_table_token_7_th interest income for the year ended december 31 , 2015 , remained flat compared to the same period in 2014. interest income for the year ended december 31 , 2014 , increased by $ 0.1 million , or 65 % , compared to the same period in 2013 due to higher average marketable securities balance in 2014 as compared to 2013 , resulting from the october 2013 common stock and preferred stock offerings which resulted in net proceeds of approximately $ 80.9 and $ 44.2 million , respectively . 34 interest expense for the year ended december 31 , 2015 in creased by $ 0.5 million or 1,534 % compared to the same period in 201 4 due to interest expense related to the loan and security agreement ( the “ loan agreement ” ) entered into with hercules technology growth capital , inc. ( “ hercules ” ) in december 2014 . interest expense for the year ended december 31 , 2014 increa sed over the same period in 2013 due to the accretion of interest expense related t o the loan agreement with hercules . other income ( loss ) for the year ended december 31 , 2015 decreased by $ 0.1 million or 27 % , compared to the same period in 2014 due to gain on foreign currency transactions resulting from fluctuations in the value of the euro compared to the u.s. dollar and withholding taxes paid in europe . other income ( loss ) for the year ended december 31 , 2014 increased by $ 0.8 million or 224 % , compared to the same period in 2013 due to gain on foreign currency transactions in 2014 related to fluctuations in the value of the euro compared to the u.s. dollar . during the year ended december 31 , 2015 , we recognized a one-time loss on extinguishment of debt of $ 1.7 million related to the early repayment of the outstanding loan from hercules . as of december 31 , 2015 , we have no debt outstanding . story_separator_special_tag roman ; font-weight : normal ; font-style : normal ; text-transform : none ; font-variant : normal ; `` > net c ash used in the purchases of equipment increased an additi o nal $ 38 thousand compared to the prior year and totaled $ 1.7 million a nd $ 1.6 million in 2014 and 2013 , respectively . during the year ended december 31 , 2014 , cash provided by financing activities decreased by $ 115.5 million , totaling $ 9.9 million , compared to $ 125.4 million for the year ended december 31 , 2013. cash provided by financing activities for the year ended december 31 , 2014 included net proceeds of $ 9.6 million drawn down under the loan agreement with hercules . cash provided by financing activities in 2013 included the sale of 7,957,000 shares of common stock and 43,430 shares of series b convertible preferred stock in separate underwritten public offerings for net proceeds of $ 125.1 million . additionally , proceeds from warrant exercises for the year ended december 31 , 2014 increased $ 0.2 million as compared to the same period in 2013. we currently estimate that we have sufficient cash resources to meet our anticipated cash needs through at least the next 12 months based on cash and cash equivalents and marketable securities on hand as of december 31 , 2015 , and anticipated revenues and expenditures . we expect to continue to spend substantial funds in connection with the development and manufacturing of our product candidates , particularly heplisav-b and our investigational cancer immunotherapeutic product candidate , sd-101 , human clinical trials for our other product candidates and additional applications and advancement of our technology . costs relating to hbv-23 r & d expense are declining following the last subject visit in october 2015 , and costs relating to seeking regulatory approval and preparing for the anticipated commercial launch of heplisav-b in the united states , as well as costs related to the ongoing development of sd-101 , are increasing . in order to continue these activities , we may need to raise additional funds . this may occur through strategic alliance and licensing arrangements and or future public or private debt or equity financings . sufficient funding may not be available , or if available , may be on terms that significantly dilute or otherwise adversely affect the rights of existing stockholders . if adequate funds are not available in the future , we may need to delay , reduce the scope of or put on hold the heplisav-b program or other development programs while we seek strategic alternatives , which could have an adverse impact on our ability to achieve our intended business objectives . contractual obligations the following summarizes our significant contractual obligations at december 31 , 2015 and the effect those obligations are expected to have on our liquidity and cash flows in future periods ( in thousands ) : replace_table_token_8_th we lease our facilities in berkeley , california ( the “ berkeley lease ” ) , and düsseldorf , germany ( the “ düsseldorf lease ” ) under operating leases that expire in june 2018 and march 2023 , respectively . during 2004 , we established a letter of credit with silicon valley bank as security for the berkeley lease in the amount of $ 0.4 million . the letter of credit remained outstanding as of december 31 , 2015 and is collateralized by a certificate of deposit for $ 0.4 million which has been included in restricted cash in the consolidated balance sheets as of december 31 , 2015 and 2014. under the terms of the berkeley lease , if the total amount of our cash , cash equivalents

liquidity and capital resources as of december 31 , 2015 , we had $ 196.1 million in cash , cash equivalents and marketable securities . since our inception , we have relied primarily on the proceeds from public and private sales of our equity securities , government grants and revenues from collaboration agreements to fund our operations . our funds are currently invested in short-term money market funds , u.s. government agency securities and corporate debt securities . on november 12 , 2015 , we entered into an at market issuance sales agreement ( the “ agreement ” ) with cowen and company , llc ( “ cowen ” ) under which we may offer and sell our common stock having aggregate sales proceeds of up to $ 90 million from time to time through cowen as our sales agent . sales of our common stock through cowen , if any , will be made by means of ordinary brokers ' transactions on the nasdaq capital market or otherwise at market prices prevailing at the time of sale , in block transactions , or as otherwise agreed upon by us and cowen . cowen will use commercially reasonable efforts to sell our common stock from time to time , based upon instructions from us ( including any price , time or size limits or other customary parameters or conditions we may impose ) . we will pay cowen a commission of up to 3.0 % of the gross sales proceeds of any common stock sold through cowen under the agreement .


 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.
     ```liquidity and capital resources as of december 31 , 2015 , we had $ 196.1 million in cash , cash equivalents and marketable securities . since our inception , we have relied primarily on the proceeds from public and private sales of our equity securities , government grants and revenues from collaboration agreements to fund our operations . our funds are currently invested in short-term money market funds , u.s. government agency securities and corporate debt securities . on november 12 , 2015 , we entered into an at market issuance sales agreement ( the “ agreement ” ) with cowen and company , llc ( “ cowen ” ) under which we may offer and sell our common stock having aggregate sales proceeds of up to $ 90 million from time to time through cowen as our sales agent . sales of our common stock through cowen , if any , will be made by means of ordinary brokers ' transactions on the nasdaq capital market or otherwise at market prices prevailing at the time of sale , in block transactions , or as otherwise agreed upon by us and cowen . cowen will use commercially reasonable efforts to sell our common stock from time to time , based upon instructions from us ( including any price , time or size limits or other customary parameters or conditions we may impose ) . we will pay cowen a commission of up to 3.0 % of the gross sales proceeds of any common stock sold through cowen under the agreement .
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 Suspicious Activity Report : product revenue will depend on our ability to receive regulatory approvals for , and successfully market , our drug candidates . we have yet to generate any revenues from product sales and have recorded an accumulated deficit of $ 699.7 million at december 31 , 2015. these losses have resulted principally from costs incurred in connection with research and development activities , compensation and other related personnel costs and general corporate expenses . research and development activities include costs of outside contracted services including clinical trial costs , manufacturing and process development costs , research costs and other consulting services . salaries and other personnel-related costs include non-cash stock-based compensation associated with options and other equity awards granted to employees . general corporate expenses include outside services such as accounting , consulting , business development , commercial , investor relations , insurance services and legal costs . our operating results may fluctuate substantially from period to period principally as a result of the timing of preclinical activities and other activities related to clinical trials for our drug candidates . since our inception , we have relied primarily on the proceeds from public and private sales of our equity securities , government grants and revenues from collaboration agreements to fund our operations . we expect to continue to spend substantial funds in connection with the development and manufacturing of our product candidates , particularly heplisav-b and our investigational cancer immunotherapeutic product candidate , sd-101 , human clinical trials for our other product candidates and additional applications and advancement of our technology . costs relating to hbv-23 declined following the last subject visit in october 2015 , but costs relating to seeking regulatory approval and preparing for the anticipated commercial launch of heplisav-b in the united states , as well as costs related to the ongoing development of sd-101 and our other cancer immunotherapeutic research and development programs , are increasing . in order to continue these activities , we may need to raise additional funds . this may occur through strategic alliance and licensing arrangements and or future public or private debt and equity financings . if adequate funds are not available in the future , we may need to delay , reduce the scope of or put on hold the heplisav-b program or other development programs while we seek strategic alternatives . 29 critical accounting policies and the use of estimates the accompanying discussion and analysis of our financial condition and results of operations are based upon our consolidated financial statements and the related disclosures , which have been prepared in accordance with u.s. generally accepted accounting principles . the preparation of these financial statements requires us to make estimates , assumptions and judgments that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the balance sheet dates and the reported amounts of revenues and expenses for the periods presented . on an ongoing basis , we evaluate our estimates , assumptions and judgments described below that have the greatest potential impact on our consolidated financial statements , including those related to revenue recognition , research and development activities and stock-based compensation . we base our estimates on historical experience and on various other assumptions that we believe to be reasonable under the circumstances , the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources . accounting assumptions and estimates are inherently uncertain and actual results may differ materially from these estimates under different assumptions or conditions . while our significant accounting policies are more fully described in note 2 to the consolidated financial statements , we believe the following critical accounting policies reflect the more significant judgments and estimates used in the preparation of our financial statements . revenue recognition our revenues consist of amounts earned from collaborations , grants and fees from services and licenses . we enter into license and manufacturing agreements and collaborative research and development arrangements with pharmaceutical and biotechnology partners that may involve multiple deliverables . our arrangements may include one or more of the following elements : upfront license payments , cost reimbursement for the performance of research and development activities , milestone payments , other contingent payments , contract manufacturing service fees , royalties and license fees . each deliverable in the arrangement is evaluated to determine whether it meets the criteria to be accounted for as a separate unit of accounting or whether it should be combined with other deliverables . in order to account for the multiple-element arrangements , the company identifies the deliverables included within the arrangement and evaluates which deliverables represent separate units of accounting . analyzing the arrangement to identify deliverables requires the use of judgment , and each deliverable may be an obligation to deliver services , a right or license to use an asset , or another performance obligation . we recognize revenue when there is persuasive evidence that an arrangement exists , delivery has occurred or services have been rendered , the price is fixed or determinable and collectability is reasonably assured . non-refundable upfront fees received for license and collaborative agreements entered into prior to january 1 , 2011 and other payments under collaboration agreements where we have continuing performance obligations related to the payments are deferred and recognized over our estimated performance period . revenue is recognized on a ratable basis , unless we determine that another method is more appropriate , through the date at which our performance obligations are completed . management makes its best estimate of the period over which we expect to fulfill our performance obligations , which may include clinical development activities . given the uncertainties of research and development collaborations , significant judgment is required to determine the duration of the performance period . story_separator_special_tag the following is a summary of our interest income and expense , other income , and loss on extinguishment of debt ( in thousands , except for percentages ) : replace_table_token_7_th interest income for the year ended december 31 , 2015 , remained flat compared to the same period in 2014. interest income for the year ended december 31 , 2014 , increased by $ 0.1 million , or 65 % , compared to the same period in 2013 due to higher average marketable securities balance in 2014 as compared to 2013 , resulting from the october 2013 common stock and preferred stock offerings which resulted in net proceeds of approximately $ 80.9 and $ 44.2 million , respectively . 34 interest expense for the year ended december 31 , 2015 in creased by $ 0.5 million or 1,534 % compared to the same period in 201 4 due to interest expense related to the loan and security agreement ( the “ loan agreement ” ) entered into with hercules technology growth capital , inc. ( “ hercules ” ) in december 2014 . interest expense for the year ended december 31 , 2014 increa sed over the same period in 2013 due to the accretion of interest expense related t o the loan agreement with hercules . other income ( loss ) for the year ended december 31 , 2015 decreased by $ 0.1 million or 27 % , compared to the same period in 2014 due to gain on foreign currency transactions resulting from fluctuations in the value of the euro compared to the u.s. dollar and withholding taxes paid in europe . other income ( loss ) for the year ended december 31 , 2014 increased by $ 0.8 million or 224 % , compared to the same period in 2013 due to gain on foreign currency transactions in 2014 related to fluctuations in the value of the euro compared to the u.s. dollar . during the year ended december 31 , 2015 , we recognized a one-time loss on extinguishment of debt of $ 1.7 million related to the early repayment of the outstanding loan from hercules . as of december 31 , 2015 , we have no debt outstanding . story_separator_special_tag roman ; font-weight : normal ; font-style : normal ; text-transform : none ; font-variant : normal ; `` > net c ash used in the purchases of equipment increased an additi o nal $ 38 thousand compared to the prior year and totaled $ 1.7 million a nd $ 1.6 million in 2014 and 2013 , respectively . during the year ended december 31 , 2014 , cash provided by financing activities decreased by $ 115.5 million , totaling $ 9.9 million , compared to $ 125.4 million for the year ended december 31 , 2013. cash provided by financing activities for the year ended december 31 , 2014 included net proceeds of $ 9.6 million drawn down under the loan agreement with hercules . cash provided by financing activities in 2013 included the sale of 7,957,000 shares of common stock and 43,430 shares of series b convertible preferred stock in separate underwritten public offerings for net proceeds of $ 125.1 million . additionally , proceeds from warrant exercises for the year ended december 31 , 2014 increased $ 0.2 million as compared to the same period in 2013. we currently estimate that we have sufficient cash resources to meet our anticipated cash needs through at least the next 12 months based on cash and cash equivalents and marketable securities on hand as of december 31 , 2015 , and anticipated revenues and expenditures . we expect to continue to spend substantial funds in connection with the development and manufacturing of our product candidates , particularly heplisav-b and our investigational cancer immunotherapeutic product candidate , sd-101 , human clinical trials for our other product candidates and additional applications and advancement of our technology . costs relating to hbv-23 r & d expense are declining following the last subject visit in october 2015 , and costs relating to seeking regulatory approval and preparing for the anticipated commercial launch of heplisav-b in the united states , as well as costs related to the ongoing development of sd-101 , are increasing . in order to continue these activities , we may need to raise additional funds . this may occur through strategic alliance and licensing arrangements and or future public or private debt or equity financings . sufficient funding may not be available , or if available , may be on terms that significantly dilute or otherwise adversely affect the rights of existing stockholders . if adequate funds are not available in the future , we may need to delay , reduce the scope of or put on hold the heplisav-b program or other development programs while we seek strategic alternatives , which could have an adverse impact on our ability to achieve our intended business objectives . contractual obligations the following summarizes our significant contractual obligations at december 31 , 2015 and the effect those obligations are expected to have on our liquidity and cash flows in future periods ( in thousands ) : replace_table_token_8_th we lease our facilities in berkeley , california ( the “ berkeley lease ” ) , and düsseldorf , germany ( the “ düsseldorf lease ” ) under operating leases that expire in june 2018 and march 2023 , respectively . during 2004 , we established a letter of credit with silicon valley bank as security for the berkeley lease in the amount of $ 0.4 million . the letter of credit remained outstanding as of december 31 , 2015 and is collateralized by a certificate of deposit for $ 0.4 million which has been included in restricted cash in the consolidated balance sheets as of december 31 , 2015 and 2014. under the terms of the berkeley lease , if the total amount of our cash , cash equivalents

