we received net proceeds of approximately $ 163.0 million from the ipo , after deducting underwriters ' discounts and commissions of $ 12.6 million and offering costs of $ 3.7 million . prior to our ipo , our primary sources of capital were private placements of preferred stock , debt financing arrangements and revenue from sales of our products . since inception , we had raised a total of approximately $ 54.2 million in net proceeds from private placements of preferred stock . as of december 31 , 2020 , we had cash and cash 97 equivalents and short-term investments of $ 16 4.2 million , no long-term debt outstanding and an accumulated deficit of $ 2 7.4 million . for the year ended december 31 , 2020 , we generated revenue of $ 139.7 million , with a gross margin of 90.6 % and net income of $ 13.8 million , compared to revenue of $ 51.1 million , with a gross margin of 88.4 % and net loss of $ 1.2 million for the year ended december 31 , 2019. covid-19 in december 2019 , a novel strain of coronavirus , sars-cov-2 , was identified in wuhan , china . since then , sars-cov-2 , and the resulting disease , covid-19 , has spread to most countries , including all 50 states in the united states . in response to the pandemic , numerous state and local jurisdictions imposed and may continue to impose from time to time “ shelter-in-place ” orders , quarantines , executive orders and similar government orders and restrictions for their residents to control the spread of covid-19 . for example , in the united states , governmental authorities recommended , and in certain cases required , that elective , specialty and other procedures and appointments be suspended or canceled to avoid non-essential patient exposure to medical environments and potential infection with covid-19 and to focus limited resources and personnel capacity toward the treatment of covid-19 patients . similarly , in march 2020 , the governor of california , where our headquarters are located , issued a “ stay at home ” order limiting non-essential activities , travel and business operations . in december 2020 , the governor of california issued an additional regional “ stay at home ” order with tiered restrictions based on each region 's icu availability . such orders or restrictions resulted in reduced operations at our headquarters ( including our manufacturing facility ) , work stoppages , slowdowns and delays , travel restrictions and cancellation of events . taken as a whole , these orders and restrictions significantly decreased the number of procedures performed using our products , particularly during the second quarter of 2020 , and otherwise negatively impacted our operations , including new customer procurement and onboarding . in response to the impact of covid-19 , beginning in the second quarter of 2020 , we implemented a variety of measures to help us manage through its impact and position us to resume operations quickly and efficiently once these restrictions were lifted . these measures existed across several operational areas and included : continuing to build our team , including identifying and recruiting our next group of new sales representatives ; enhancing our physician outreach and training with the launch of our clot warrior academy consisting of a series of live webinars and an online education portal ; continuing to support procedures using our products both in-person and virtually ; adapting , expanding and improving our sales training programs and customer engagement to address the current environment ; continuing to expand our engineering infrastructure and focusing on organic opportunities ; producing approximately four months ' worth of inventory before temporarily suspending production in april 2020 ; continuing to protect and support our employees , including no layoffs , furloughs or compensation reductions to date ; executing a successful work-from-home strategy for administrative functions that includes launching various efficiency projects in information technology , accounting and operations ; monitoring and reviewing recent case studies of vte patients suffering from covid-19 ; initiating market assessment and commercial entry planning for our international expansion ; and accessing the remaining $ 10.0 million on our term loan on march 23 , 2020 , which was repaid in full along with all our long term-debt in august 2020. despite the negative impacts from covid-19 , for the year ended december 31 , 2020 , we completed our ipo and approximately 13,200 procedures were performed using our products , compared to approximately 4,600 98 procedures in the year ended december 31 , 2019 . during the second quarter of 2020 , we experienced disruptions to our procedure volume beginning in mid-march as a result of covid-19 , and weekly procedure volumes declined by approximately 40 % by mid-april when compared to weekly procedure volumes in early march . the decrease in procedure volume impacted dvt procedures and pe procedures relatively equally , with both types of procedures declining during this period . however , w e saw a recovery in procedure volume in june that was higher than our pre - covid-19 peak . during the third and fourth quarter s , we saw continued sequential growth beyond previous quarters . while we are encouraged by our third and fourth quarters results , we are aware that the actual and perceived impact of covid-19 is changing and can not be predicted . as a result , we can not assure you that our recent procedure volumes are indicative of future results or that we will not experience additional negative impacts associated with covid-19 , which could be significant . the covid-19 pandemic has negatively impacted our business , financial condition and results of operations by significantly decreasing and delaying the number of procedures performed using our products , and we expect the pandemic could continue to negatively impact our business , financial condition and results of operations . story_separator_special_tag from the exercise of stock options . net cash provided by financing activities for the year ended december 31 , 2018 of $ 26.8 million primarily relates to net proceeds of $ 26.9 million from the issuance of our series c convertible preferred stock and $ 0.2 million of debt financing costs . off-balance sheet arrangements we do not have any off-balance sheet arrangements , as defined by applicable regulations of the u.s. securities and exchange commission , that are reasonably likely to have a current or future material effect on our financial condition , results of operations , liquidity , capital expenditures or capital resources . contractual obligations and commitments the following table shows our contractual obligations due by period as of december 31 , 2020 : replace_table_token_12_th 106 critical accounting policies and estimates management 's discussion and analysis of our financial condition and results of operations is based on our consolidated financial statements , which have been prepared in accordance with u.s. gaap . the preparation of these consolidated financial statements requires us to make estimates and assumptions for the reported amounts of assets , liabilities , revenue , expenses and related disclosures . our estimates are based on our historical experience and on various other factors that we believe are reasonable under the circumstances , the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources . actual results may differ from these estimates under different assumptions or conditions and any such differences may be material . while our significant accounting policies are more fully described in the note 2 to our audited consolidated financial statements appearing elsewhere in this annual report on form 10-k , we believe the following discussion addresses our most critical accounting policies , which are those that are most important to our financial condition and results of operations and require our most difficult , subjective and complex judgments . revenue recognition on january 1 , 2019 , we adopted accounting standards codification ( “ asc ” ) 606 , revenue from contracts with customers , using the modified retrospective method applied to contracts which were not completed as of that date . revenue for reporting periods beginning after january 1 , 2019 are presented under asc 606 , while prior period amounts are not adjusted and continue to be reported in accordance with our historic accounting under asc 605 , revenue recognition . under asc 606 , revenue is recognized when a customer obtains control of promised goods or services , in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services . to determine whether revenue recognition for arrangements is within the scope of asc 606 , we perform the following five steps : ( i ) identify the contract ( s ) with a customer ; ( ii ) identify the performance obligations in the contract ; ( iii ) determine the transaction price ; ( iv ) allocate the transaction price to the performance obligations in the contract ; and ( v ) recognize revenue when ( or as ) the entity satisfies a performance obligation . product sales of the flowtriever and clottriever systems are made to hospitals in the united states utilizing our direct sales force . revenue is comprised of product revenue net of returns , administration fees and sales rebates . performance obligation —we have revenue arrangements that consist of a single performance obligation , delivery of our products . the satisfaction of this performance obligation occurs with the transfer of control of our product to our customers , either upon shipment or delivery of the product . revenue is measured as the amount of consideration we expect to receive in exchange for transferring goods . the amount of revenue that is recognized is based on the transaction price , which represents the invoiced amount and includes estimates of variable consideration such as rebate and administrative fees , where applicable . we provide a 30-day unconditional right of return period . we establish estimated provisions for returns at the time of sale based on historical experience . historically , the actual product returns have been immaterial to our consolidated financial statements . assuming all other revenue recognition criteria have been met , we recognize revenue for arrangements where the company has satisfied its performance obligation of delivering the product . for sales where our sales representatives hand deliver products directly to the hospital , control of the products transfers to the customer upon such hand delivery . for sales where products are shipped , control of the products transfers either upon shipment or delivery of the products to the customer , depending on the shipping terms and conditions . as of december 31 , 2020 and 2019 , we recorded $ 498,000 and $ 330,000 , respectively , of unbilled receivables , which are included in accounts receivable , net , in the accompanying consolidated balance sheets . 107 revenue for clottriever and flowtriever products as a percentage of total revenue was derived as follow : replace_table_token_13_th we offer payment terms to our customers of less than three months and these terms do not include a significant financing component . we exclude taxes assessed by governmental authorities on revenue-producing transactions from the measurement of the transaction price . we offer a standard warranty to all customers . we do not sell any warranties on a standalone basis . our warranty provides that its products are free of material defects and conform to specifications , and we offer to repair , replace or refund the purchase price of defective products . this assurance does not constitute a service and is not considered a separate performance obligation . we estimate warranty liabilities at the time of revenue recognition and record it as a charge to cost of goods sold . costs associated with

liquidity and capital resources to date , our primary sources of capital have been the net proceeds we received through private placements of preferred stock , debt financing agreements , the sale of common stock in our ipo , and revenue from the sale of our products . on may 27 , 2020 , we completed our ipo , including the underwriters full exercise of their over-allotment option , selling 9,432,949 shares of our common stock at $ 19.00 per share . upon completion of our ipo , we received net proceeds of approximately $ 163.0 million , after deducting underwriting discounts and commissions and offering expenses . in august 2020 , we repaid in full the $ 30.0 million of principal owed under the credit facility with signature bank . as of december 31 , 2020 , we had cash and cash equivalents of $ 114 million , short-term investments of $ 50.0 million , and an accumulated deficit of $ 27.4 million . in september 2020 , we entered into a new revolving credit agreement with bank of america which provides for loans up to a maximum of $ 30 million . as of december 31 , 2020 , we had no principal outstanding under the credit agreement and the amount available to borrow was approximately $ 28.5 million . based on our current planned operations , we expect that our cash and cash equivalents and available borrowings will enable us to fund our operating expenses for at least 12 months from the date hereof . if our available cash balances and anticipated cash flow from operations are insufficient to satisfy our liquidity requirements including because of lower demand for our products as a result of the risks described in this annual report , we may seek to sell additional common or preferred equity or convertible debt securities , enter into an additional credit facility or another form of third-party funding or seek other debt financing .


 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 to date , our primary sources of capital have been the net proceeds we received through private placements of preferred stock , debt financing agreements , the sale of common stock in our ipo , and revenue from the sale of our products . on may 27 , 2020 , we completed our ipo , including the underwriters full exercise of their over-allotment option , selling 9,432,949 shares of our common stock at $ 19.00 per share . upon completion of our ipo , we received net proceeds of approximately $ 163.0 million , after deducting underwriting discounts and commissions and offering expenses . in august 2020 , we repaid in full the $ 30.0 million of principal owed under the credit facility with signature bank . as of december 31 , 2020 , we had cash and cash equivalents of $ 114 million , short-term investments of $ 50.0 million , and an accumulated deficit of $ 27.4 million . in september 2020 , we entered into a new revolving credit agreement with bank of america which provides for loans up to a maximum of $ 30 million . as of december 31 , 2020 , we had no principal outstanding under the credit agreement and the amount available to borrow was approximately $ 28.5 million . based on our current planned operations , we expect that our cash and cash equivalents and available borrowings will enable us to fund our operating expenses for at least 12 months from the date hereof . if our available cash balances and anticipated cash flow from operations are insufficient to satisfy our liquidity requirements including because of lower demand for our products as a result of the risks described in this annual report , we may seek to sell additional common or preferred equity or convertible debt securities , enter into an additional credit facility or another form of third-party funding or seek other debt financing .
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 Suspicious Activity Report : we received net proceeds of approximately $ 163.0 million from the ipo , after deducting underwriters ' discounts and commissions of $ 12.6 million and offering costs of $ 3.7 million . prior to our ipo , our primary sources of capital were private placements of preferred stock , debt financing arrangements and revenue from sales of our products . since inception , we had raised a total of approximately $ 54.2 million in net proceeds from private placements of preferred stock . as of december 31 , 2020 , we had cash and cash 97 equivalents and short-term investments of $ 16 4.2 million , no long-term debt outstanding and an accumulated deficit of $ 2 7.4 million . for the year ended december 31 , 2020 , we generated revenue of $ 139.7 million , with a gross margin of 90.6 % and net income of $ 13.8 million , compared to revenue of $ 51.1 million , with a gross margin of 88.4 % and net loss of $ 1.2 million for the year ended december 31 , 2019. covid-19 in december 2019 , a novel strain of coronavirus , sars-cov-2 , was identified in wuhan , china . since then , sars-cov-2 , and the resulting disease , covid-19 , has spread to most countries , including all 50 states in the united states . in response to the pandemic , numerous state and local jurisdictions imposed and may continue to impose from time to time “ shelter-in-place ” orders , quarantines , executive orders and similar government orders and restrictions for their residents to control the spread of covid-19 . for example , in the united states , governmental authorities recommended , and in certain cases required , that elective , specialty and other procedures and appointments be suspended or canceled to avoid non-essential patient exposure to medical environments and potential infection with covid-19 and to focus limited resources and personnel capacity toward the treatment of covid-19 patients . similarly , in march 2020 , the governor of california , where our headquarters are located , issued a “ stay at home ” order limiting non-essential activities , travel and business operations . in december 2020 , the governor of california issued an additional regional “ stay at home ” order with tiered restrictions based on each region 's icu availability . such orders or restrictions resulted in reduced operations at our headquarters ( including our manufacturing facility ) , work stoppages , slowdowns and delays , travel restrictions and cancellation of events . taken as a whole , these orders and restrictions significantly decreased the number of procedures performed using our products , particularly during the second quarter of 2020 , and otherwise negatively impacted our operations , including new customer procurement and onboarding . in response to the impact of covid-19 , beginning in the second quarter of 2020 , we implemented a variety of measures to help us manage through its impact and position us to resume operations quickly and efficiently once these restrictions were lifted . these measures existed across several operational areas and included : continuing to build our team , including identifying and recruiting our next group of new sales representatives ; enhancing our physician outreach and training with the launch of our clot warrior academy consisting of a series of live webinars and an online education portal ; continuing to support procedures using our products both in-person and virtually ; adapting , expanding and improving our sales training programs and customer engagement to address the current environment ; continuing to expand our engineering infrastructure and focusing on organic opportunities ; producing approximately four months ' worth of inventory before temporarily suspending production in april 2020 ; continuing to protect and support our employees , including no layoffs , furloughs or compensation reductions to date ; executing a successful work-from-home strategy for administrative functions that includes launching various efficiency projects in information technology , accounting and operations ; monitoring and reviewing recent case studies of vte patients suffering from covid-19 ; initiating market assessment and commercial entry planning for our international expansion ; and accessing the remaining $ 10.0 million on our term loan on march 23 , 2020 , which was repaid in full along with all our long term-debt in august 2020. despite the negative impacts from covid-19 , for the year ended december 31 , 2020 , we completed our ipo and approximately 13,200 procedures were performed using our products , compared to approximately 4,600 98 procedures in the year ended december 31 , 2019 . during the second quarter of 2020 , we experienced disruptions to our procedure volume beginning in mid-march as a result of covid-19 , and weekly procedure volumes declined by approximately 40 % by mid-april when compared to weekly procedure volumes in early march . the decrease in procedure volume impacted dvt procedures and pe procedures relatively equally , with both types of procedures declining during this period . however , w e saw a recovery in procedure volume in june that was higher than our pre - covid-19 peak . during the third and fourth quarter s , we saw continued sequential growth beyond previous quarters . while we are encouraged by our third and fourth quarters results , we are aware that the actual and perceived impact of covid-19 is changing and can not be predicted . as a result , we can not assure you that our recent procedure volumes are indicative of future results or that we will not experience additional negative impacts associated with covid-19 , which could be significant . the covid-19 pandemic has negatively impacted our business , financial condition and results of operations by significantly decreasing and delaying the number of procedures performed using our products , and we expect the pandemic could continue to negatively impact our business , financial condition and results of operations . story_separator_special_tag from the exercise of stock options . net cash provided by financing activities for the year ended december 31 , 2018 of $ 26.8 million primarily relates to net proceeds of $ 26.9 million from the issuance of our series c convertible preferred stock and $ 0.2 million of debt financing costs . off-balance sheet arrangements we do not have any off-balance sheet arrangements , as defined by applicable regulations of the u.s. securities and exchange commission , that are reasonably likely to have a current or future material effect on our financial condition , results of operations , liquidity , capital expenditures or capital resources . contractual obligations and commitments the following table shows our contractual obligations due by period as of december 31 , 2020 : replace_table_token_12_th 106 critical accounting policies and estimates management 's discussion and analysis of our financial condition and results of operations is based on our consolidated financial statements , which have been prepared in accordance with u.s. gaap . the preparation of these consolidated financial statements requires us to make estimates and assumptions for the reported amounts of assets , liabilities , revenue , expenses and related disclosures . our estimates are based on our historical experience and on various other factors that we believe are reasonable under the circumstances , the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources . actual results may differ from these estimates under different assumptions or conditions and any such differences may be material . while our significant accounting policies are more fully described in the note 2 to our audited consolidated financial statements appearing elsewhere in this annual report on form 10-k , we believe the following discussion addresses our most critical accounting policies , which are those that are most important to our financial condition and results of operations and require our most difficult , subjective and complex judgments . revenue recognition on january 1 , 2019 , we adopted accounting standards codification ( “ asc ” ) 606 , revenue from contracts with customers , using the modified retrospective method applied to contracts which were not completed as of that date . revenue for reporting periods beginning after january 1 , 2019 are presented under asc 606 , while prior period amounts are not adjusted and continue to be reported in accordance with our historic accounting under asc 605 , revenue recognition . under asc 606 , revenue is recognized when a customer obtains control of promised goods or services , in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services . to determine whether revenue recognition for arrangements is within the scope of asc 606 , we perform the following five steps : ( i ) identify the contract ( s ) with a customer ; ( ii ) identify the performance obligations in the contract ; ( iii ) determine the transaction price ; ( iv ) allocate the transaction price to the performance obligations in the contract ; and ( v ) recognize revenue when ( or as ) the entity satisfies a performance obligation . product sales of the flowtriever and clottriever systems are made to hospitals in the united states utilizing our direct sales force . revenue is comprised of product revenue net of returns , administration fees and sales rebates . performance obligation —we have revenue arrangements that consist of a single performance obligation , delivery of our products . the satisfaction of this performance obligation occurs with the transfer of control of our product to our customers , either upon shipment or delivery of the product . revenue is measured as the amount of consideration we expect to receive in exchange for transferring goods . the amount of revenue that is recognized is based on the transaction price , which represents the invoiced amount and includes estimates of variable consideration such as rebate and administrative fees , where applicable . we provide a 30-day unconditional right of return period . we establish estimated provisions for returns at the time of sale based on historical experience . historically , the actual product returns have been immaterial to our consolidated financial statements . assuming all other revenue recognition criteria have been met , we recognize revenue for arrangements where the company has satisfied its performance obligation of delivering the product . for sales where our sales representatives hand deliver products directly to the hospital , control of the products transfers to the customer upon such hand delivery . for sales where products are shipped , control of the products transfers either upon shipment or delivery of the products to the customer , depending on the shipping terms and conditions . as of december 31 , 2020 and 2019 , we recorded $ 498,000 and $ 330,000 , respectively , of unbilled receivables , which are included in accounts receivable , net , in the accompanying consolidated balance sheets . 107 revenue for clottriever and flowtriever products as a percentage of total revenue was derived as follow : replace_table_token_13_th we offer payment terms to our customers of less than three months and these terms do not include a significant financing component . we exclude taxes assessed by governmental authorities on revenue-producing transactions from the measurement of the transaction price . we offer a standard warranty to all customers . we do not sell any warranties on a standalone basis . our warranty provides that its products are free of material defects and conform to specifications , and we offer to repair , replace or refund the purchase price of defective products . this assurance does not constitute a service and is not considered a separate performance obligation . we estimate warranty liabilities at the time of revenue recognition and record it as a charge to cost of goods sold . costs associated with

