in 2016 , 43 % of our product revenues were from devices in the marketplace for over two years and 37 % for devices in the marketplace for one to two years and 20 % for devices in the marketplace for less than one year . 43 we believe demand is growing rapidly for our antenna solutions and there is a significant market opportunity . as the ability to provide mobile internet access has grown , our solutions and expertise have become more important to prospects and customers . as a passive component , embedded antennas can be viewed as a commodity . however , our design , engineering , and resea rch show that antenna selection , placement , and testing can have significant improvements in device performance . we believe that we are chosen when performance is a more significant factor than price , and our distinctive focus on superior designs that prov ide increased range and throughput has allowed us to build a leadership position in the in-home wlan antenna market . factors affecting our operating results we believe that our performance and future success depend upon several factors , including the average selling price of our products per device , the number of antennas per device , manufacturing costs , investments in our growth , and our ability to diversify the number of devices that incorporate our antenna products . our customers are extremely price conscious , and our operating results are affected by pricing pressure which may force us to lower prices below our current prices . in addition , a few end-customer devices which incorporate our antenna products comprise a significant amount of our sales , and the discontinuation or modification of such devices may materially and adversely affect our sales and results of operations . we have seen the number of devices increase 55 % and number of antennas per device increase 18 % for the year ended december 31 , 2016 when compared to the year ended december 31 , 2015. our ability to maintain or increase our sales depends on new and existing end-customers selecting our antenna solutions for their devices and depends on investments in our growth to address customer needs , target new end markets , develop our product offerings and technology solutions and expand internationally . while each of these areas presents significant opportunities for us , they also pose significant risks and challenges we must successfully address . we discuss many of these risks , uncertainties and other factors in this annual report in greater detail under the section entitled “ risk factors . ” key components of our results of operations and financial condition sales we primarily generate revenue from the sales of our products . as discussed further in “ critical accounting policies and significant judgments and estimates ” below , we recognize revenue when persuasive evidence of an arrangement exists , delivery has occurred , the fee is fixed or determinable , and collectability is reasonably assured . we generally recognize sales at the time of shipment to our customers , provided that all other revenue recognition criteria have been met . although currently insignificant , we may also generate service revenue derived from agreements to provide design , engineering , and testing to a customer . cost of goods sold the cost of goods sold reflects the cost of producing antenna products that are shipped for our customers ' devices . this primarily includes manufacturing costs of our products payable to our third-party contract manufacturers . the cost of goods sold that we generate from services provided to customers primarily includes personnel costs . operating expenses our operating expenses are classified into three categories : research and development , sales and marketing , and general and administrative . for each category , the largest component is personnel costs , which includes salaries , employee benefit costs , bonuses , and stock-based compensation . operating expenses also include allocated overhead costs for depreciation of equipment , facilities and information technology . allocated costs for facilities consist of leasehold improvements and rent . operating expenses are generally recognized as incurred . research and development . research and development expenses primarily consist of personnel and facility-related costs attributable to our engineering research and development personnel . these expenses include work related to the design , engineering and testing of antenna designs , and antenna integration , validation and testing of customer devices . these expenses include salaries , including stock-based compensation , benefits , bonuses , travel , communications , and similar costs , and depreciation and allocated operating expenses such as office supplies , 44 premises expenses , insurance and corporate legal expenses . we may also incur expenses from consultants and for prototyping new antenna solutions . we expect research and development expense to increase in absolute dollars as we inc rease our research and development headcount to further strengthen and enhance our antenna design and integration capabilities and invest in the development of new solutions and markets , although our research and development expense may fluctuate as a perc entage of total sales . sales and marketing . sales and marketing expenses primarily consist of personnel and facility-related costs for our sales , marketing , and business development personnel , stock-based compensation and bonuses earned by our sales personnel , and commissions earned by our third-party sales representative firms . sales and marketing expense also includes the costs of trade shows , marketing programs , promotional materials , demonstration equipment , travel , recruiting , and allocated costs for certain facilities . we expect sales and marketing expense to continue to increase in absolute dollars as we increase the size of our sales and marketing organizations in support of our investment in our growth opportunities , although our sales and marketing expense may fluctuate as a percentage of total sales . general and administrative . story_separator_special_tag the grant date fair value of stock-based awards is expensed on a straight-line basis over the vesting period of the respective award . we account for stock-based compensation arrangements with non-employees using a fair value approach . the fair value of these options is measured using the black-scholes-merton option-pricing model reflecting the same assumptions as applied to employee options in each of the reported periods , other than the expected life , which is assumed to be the remaining contractual life of the option . the compensation costs of these arrangements are subject to remeasurement over the vesting terms as earned . we recorded stock-based compensation expense of approximately $ 0.3 million , $ 0.3 million and $ 0.7 million for the years ended december 31 , 2016 , 2015 and 2014 , respectively . we expect to continue to grant stock options and other equity-based awards in the future , and to the extent that we do , our stock-based compensation expense recognized in future periods will likely increase . the black-scholes-merton option-pricing model requires the use of highly subjective and complex assumptions , which determine the fair value of stock-based awards . if we had made different assumptions , our 52 stock-based compensation expense , net loss and net loss per share of common stock could have been significantly different . our assumptions are as follows : fair value of our common stock . prior to our initial public offering , we estimated the fair value of our common stock . see “ significant factors , assumptions and methodologies used in determining fair value of our common stock ” below . upon the closing of our initial public offering , our common stock is valued by reference to the publicly traded price of our common stock . expected term . the expected term represents the period that the stock-based awards are expected to be outstanding . our historical share option exercise experience does not provide a reasonable basis upon which to estimate an expected term because of a lack of sufficient data . therefore , we estimate the expected term by using the simplified method , which calculates the expected term as the average of the time-to-vesting and the contractual life of the options . expected volatility . we have historically been a private company . therefore , we historically estimated the expected volatility based on the average historical volatilities of publicly traded companies within our industry that we consider to be comparable to our business over a period approximately equal to the expected term . we intend to continue to consistently apply this process using the same or similar public companies until a sufficient amount of historical information regarding the volatility of our own common stock price becomes available , or unless circumstances change such that the identified companies are no longer similar to us , in which case , more suitable companies whose share prices are publicly available would be utilized in the calculation . risk-free interest rate . the risk-free interest rate is based on the u.s. treasury yield in effect at the time of grant for zero coupon u.s. treasury notes with maturities approximately equal to the expected term . expected dividend . the expected dividend is assumed to be zero as we have never paid dividends and have no current plans to pay any dividends on our common stock . expected forfeiture . we use historical data to estimate pre-vesting option forfeitures and record stock- based compensation expense only for those awards that are expected to vest . to the extent actual forfeitures differ from the estimates , the difference will be recorded as a cumulative adjustment in the period that the estimates are revised . significant factors , assumptions and methodologies used in determining fair value of our common stock we are also required to estimate the fair value of the common stock underlying our stock-based awards when performing the fair value calculations using the black-scholes-merton option-pricing model . our board of directors , with the assistance of management , determined the fair value of our common stock on each grant date . all options to purchase shares of our common stock are intended to be granted with an exercise price per share no less than the fair value per share of our common stock underlying those options on the date of grant , based on the information known to us on the date of grant . because , prior to our initial public offering , there was historically no public market for our common stock , the fair value of the common stock that underlies our stock options has historically been determined by our board of directors based upon information available to it at the time of grant , including the following : contemporaneous valuations performed by a qualified , independent appraiser ; our current and projected operating and financial performance , including our levels of available capital resources ; trends and developments in our industry ; the valuation of publicly traded companies in our sector , as well as recently completed initial public offerings and mergers and acquisitions of comparable companies ; 53 rights , preferences and privileges of our common stock compared to the rights , preferences and privileges of our other outstanding equity securities ; u.s. and global economic and capital market conditions ; the likelihood of achieving a liquidity event for the shares of common stock , such as an initial public offering or an acquisition of our company given prevailing market and sector conditions ; the illiquidity of our securities by virtue of being a private company ; business risks ; and management and board experience . our business enterprise value was estimated using a combination of two generally accepted approaches : the income approach and the market-based approach . the income approach estimates enterprise value based on the estimated present value of future net cash flows the business is expected to generate over its remaining

liquidity and capital resources we had cash and cash equivalents of $ 45.2 million at december 31 , 2016. cash and cash equivalents consist of cash . we did not have any short-term or long-term investments . in august 2016 , we completed our initial public offering , or ipo , and received net proceeds of approximately $ 10.8 million , including the sale of shares pursuant to the exercise of the underwriters ' over-allotment option and after deducting underwriting discounts and commissions and offering-related transaction costs . in december 2016 , we completed our public offering of common stock and received net proceeds of approximately $ 26.0 million , including the sale of shares pursuant to the exercise of the underwriters ' over-allotment option and after deducting underwriting discounts and commissions and estimated offering-related transaction costs . before 2013 , we had incurred net losses in each year since our inception . as a result , we had an accumulated deficit of $ 43.6 million at december 31 , 2016. since inception , we have primarily financed our operations and capital expenditures through private sales of preferred stock , convertible promissory notes and cash flows from our operations . we have raised an aggregate of $ 29.5 million in net proceeds from the issuance of our preferred stock and convertible promissory notes and $ 36.8 million from the sale of common stock in public offerings . as of december 31 , 2016 , we had approximately $ 2.7 million outstanding under a term loan and approximately $ 0.1 million outstanding under a growth capital term loan pursuant to our amended and restated loan and security agreement with silicon valley bank . in addition , under our amended and restated loan and security agreement with silicon valley bank , we have a revolving line of credit for $ 3.0 million . as of december 31 , 2016 , there was no balance owed on the line of credit .


 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 we had cash and cash equivalents of $ 45.2 million at december 31 , 2016. cash and cash equivalents consist of cash . we did not have any short-term or long-term investments . in august 2016 , we completed our initial public offering , or ipo , and received net proceeds of approximately $ 10.8 million , including the sale of shares pursuant to the exercise of the underwriters ' over-allotment option and after deducting underwriting discounts and commissions and offering-related transaction costs . in december 2016 , we completed our public offering of common stock and received net proceeds of approximately $ 26.0 million , including the sale of shares pursuant to the exercise of the underwriters ' over-allotment option and after deducting underwriting discounts and commissions and estimated offering-related transaction costs . before 2013 , we had incurred net losses in each year since our inception . as a result , we had an accumulated deficit of $ 43.6 million at december 31 , 2016. since inception , we have primarily financed our operations and capital expenditures through private sales of preferred stock , convertible promissory notes and cash flows from our operations . we have raised an aggregate of $ 29.5 million in net proceeds from the issuance of our preferred stock and convertible promissory notes and $ 36.8 million from the sale of common stock in public offerings . as of december 31 , 2016 , we had approximately $ 2.7 million outstanding under a term loan and approximately $ 0.1 million outstanding under a growth capital term loan pursuant to our amended and restated loan and security agreement with silicon valley bank . in addition , under our amended and restated loan and security agreement with silicon valley bank , we have a revolving line of credit for $ 3.0 million . as of december 31 , 2016 , there was no balance owed on the line of credit .
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 Suspicious Activity Report : in 2016 , 43 % of our product revenues were from devices in the marketplace for over two years and 37 % for devices in the marketplace for one to two years and 20 % for devices in the marketplace for less than one year . 43 we believe demand is growing rapidly for our antenna solutions and there is a significant market opportunity . as the ability to provide mobile internet access has grown , our solutions and expertise have become more important to prospects and customers . as a passive component , embedded antennas can be viewed as a commodity . however , our design , engineering , and resea rch show that antenna selection , placement , and testing can have significant improvements in device performance . we believe that we are chosen when performance is a more significant factor than price , and our distinctive focus on superior designs that prov ide increased range and throughput has allowed us to build a leadership position in the in-home wlan antenna market . factors affecting our operating results we believe that our performance and future success depend upon several factors , including the average selling price of our products per device , the number of antennas per device , manufacturing costs , investments in our growth , and our ability to diversify the number of devices that incorporate our antenna products . our customers are extremely price conscious , and our operating results are affected by pricing pressure which may force us to lower prices below our current prices . in addition , a few end-customer devices which incorporate our antenna products comprise a significant amount of our sales , and the discontinuation or modification of such devices may materially and adversely affect our sales and results of operations . we have seen the number of devices increase 55 % and number of antennas per device increase 18 % for the year ended december 31 , 2016 when compared to the year ended december 31 , 2015. our ability to maintain or increase our sales depends on new and existing end-customers selecting our antenna solutions for their devices and depends on investments in our growth to address customer needs , target new end markets , develop our product offerings and technology solutions and expand internationally . while each of these areas presents significant opportunities for us , they also pose significant risks and challenges we must successfully address . we discuss many of these risks , uncertainties and other factors in this annual report in greater detail under the section entitled “ risk factors . ” key components of our results of operations and financial condition sales we primarily generate revenue from the sales of our products . as discussed further in “ critical accounting policies and significant judgments and estimates ” below , we recognize revenue when persuasive evidence of an arrangement exists , delivery has occurred , the fee is fixed or determinable , and collectability is reasonably assured . we generally recognize sales at the time of shipment to our customers , provided that all other revenue recognition criteria have been met . although currently insignificant , we may also generate service revenue derived from agreements to provide design , engineering , and testing to a customer . cost of goods sold the cost of goods sold reflects the cost of producing antenna products that are shipped for our customers ' devices . this primarily includes manufacturing costs of our products payable to our third-party contract manufacturers . the cost of goods sold that we generate from services provided to customers primarily includes personnel costs . operating expenses our operating expenses are classified into three categories : research and development , sales and marketing , and general and administrative . for each category , the largest component is personnel costs , which includes salaries , employee benefit costs , bonuses , and stock-based compensation . operating expenses also include allocated overhead costs for depreciation of equipment , facilities and information technology . allocated costs for facilities consist of leasehold improvements and rent . operating expenses are generally recognized as incurred . research and development . research and development expenses primarily consist of personnel and facility-related costs attributable to our engineering research and development personnel . these expenses include work related to the design , engineering and testing of antenna designs , and antenna integration , validation and testing of customer devices . these expenses include salaries , including stock-based compensation , benefits , bonuses , travel , communications , and similar costs , and depreciation and allocated operating expenses such as office supplies , 44 premises expenses , insurance and corporate legal expenses . we may also incur expenses from consultants and for prototyping new antenna solutions . we expect research and development expense to increase in absolute dollars as we inc rease our research and development headcount to further strengthen and enhance our antenna design and integration capabilities and invest in the development of new solutions and markets , although our research and development expense may fluctuate as a perc entage of total sales . sales and marketing . sales and marketing expenses primarily consist of personnel and facility-related costs for our sales , marketing , and business development personnel , stock-based compensation and bonuses earned by our sales personnel , and commissions earned by our third-party sales representative firms . sales and marketing expense also includes the costs of trade shows , marketing programs , promotional materials , demonstration equipment , travel , recruiting , and allocated costs for certain facilities . we expect sales and marketing expense to continue to increase in absolute dollars as we increase the size of our sales and marketing organizations in support of our investment in our growth opportunities , although our sales and marketing expense may fluctuate as a percentage of total sales . general and administrative . story_separator_special_tag the grant date fair value of stock-based awards is expensed on a straight-line basis over the vesting period of the respective award . we account for stock-based compensation arrangements with non-employees using a fair value approach . the fair value of these options is measured using the black-scholes-merton option-pricing model reflecting the same assumptions as applied to employee options in each of the reported periods , other than the expected life , which is assumed to be the remaining contractual life of the option . the compensation costs of these arrangements are subject to remeasurement over the vesting terms as earned . we recorded stock-based compensation expense of approximately $ 0.3 million , $ 0.3 million and $ 0.7 million for the years ended december 31 , 2016 , 2015 and 2014 , respectively . we expect to continue to grant stock options and other equity-based awards in the future , and to the extent that we do , our stock-based compensation expense recognized in future periods will likely increase . the black-scholes-merton option-pricing model requires the use of highly subjective and complex assumptions , which determine the fair value of stock-based awards . if we had made different assumptions , our 52 stock-based compensation expense , net loss and net loss per share of common stock could have been significantly different . our assumptions are as follows : fair value of our common stock . prior to our initial public offering , we estimated the fair value of our common stock . see “ significant factors , assumptions and methodologies used in determining fair value of our common stock ” below . upon the closing of our initial public offering , our common stock is valued by reference to the publicly traded price of our common stock . expected term . the expected term represents the period that the stock-based awards are expected to be outstanding . our historical share option exercise experience does not provide a reasonable basis upon which to estimate an expected term because of a lack of sufficient data . therefore , we estimate the expected term by using the simplified method , which calculates the expected term as the average of the time-to-vesting and the contractual life of the options . expected volatility . we have historically been a private company . therefore , we historically estimated the expected volatility based on the average historical volatilities of publicly traded companies within our industry that we consider to be comparable to our business over a period approximately equal to the expected term . we intend to continue to consistently apply this process using the same or similar public companies until a sufficient amount of historical information regarding the volatility of our own common stock price becomes available , or unless circumstances change such that the identified companies are no longer similar to us , in which case , more suitable companies whose share prices are publicly available would be utilized in the calculation . risk-free interest rate . the risk-free interest rate is based on the u.s. treasury yield in effect at the time of grant for zero coupon u.s. treasury notes with maturities approximately equal to the expected term . expected dividend . the expected dividend is assumed to be zero as we have never paid dividends and have no current plans to pay any dividends on our common stock . expected forfeiture . we use historical data to estimate pre-vesting option forfeitures and record stock- based compensation expense only for those awards that are expected to vest . to the extent actual forfeitures differ from the estimates , the difference will be recorded as a cumulative adjustment in the period that the estimates are revised . significant factors , assumptions and methodologies used in determining fair value of our common stock we are also required to estimate the fair value of the common stock underlying our stock-based awards when performing the fair value calculations using the black-scholes-merton option-pricing model . our board of directors , with the assistance of management , determined the fair value of our common stock on each grant date . all options to purchase shares of our common stock are intended to be granted with an exercise price per share no less than the fair value per share of our common stock underlying those options on the date of grant , based on the information known to us on the date of grant . because , prior to our initial public offering , there was historically no public market for our common stock , the fair value of the common stock that underlies our stock options has historically been determined by our board of directors based upon information available to it at the time of grant , including the following : contemporaneous valuations performed by a qualified , independent appraiser ; our current and projected operating and financial performance , including our levels of available capital resources ; trends and developments in our industry ; the valuation of publicly traded companies in our sector , as well as recently completed initial public offerings and mergers and acquisitions of comparable companies ; 53 rights , preferences and privileges of our common stock compared to the rights , preferences and privileges of our other outstanding equity securities ; u.s. and global economic and capital market conditions ; the likelihood of achieving a liquidity event for the shares of common stock , such as an initial public offering or an acquisition of our company given prevailing market and sector conditions ; the illiquidity of our securities by virtue of being a private company ; business risks ; and management and board experience . our business enterprise value was estimated using a combination of two generally accepted approaches : the income approach and the market-based approach . the income approach estimates enterprise value based on the estimated present value of future net cash flows the business is expected to generate over its remaining

