7Baggers

Silk Road Medical, Inc
(NASDAQ:SILK) 

SILK stock logo

Silk Road Medical, Inc. operates as a medical device company in the United States. The company offers various products for the treatment of carotid artery disease called transcarotid artery revascularization. Its products includes ENROUTE Transcarotid Neuroprotection System that is used to directly ...

Founded: 2007
IPO Price: $17 (Apr 04, 2019)
Full Time Employees: 224
CEO: Erica J. Rogers  
Sector: Healthcare
Industry: Medical Devices

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At a glance:
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Income Statements:
Quarterly
Annual
    Unit: USD2024-06-30 2024-03-31 2023-12-31 2023-09-30 2023-06-30 2023-03-31 2022-12-31 2022-09-30 2022-06-30 2022-03-31 2021-12-31 2021-09-30 2021-06-30 2021-03-31 2020-12-31 2020-09-30 2020-06-30 2020-03-31 2019-12-31 2019-09-30 2019-06-30 2019-03-31 
                          
      revenue
    51,242,000 48,484,000 47,270,000 44,435,000 45,298,000 40,131,000 40,071,000 37,374,000 33,173,000 28,021,000 28,265,000 24,701,000 26,456,000 22,053,000 21,134,000 20,067,000 15,094,000 18,933,000 18,633,000 17,026,000 14,928,000 12,766,000 
      yoy
    13.12% 20.81% 17.97% 18.89% 36.55% 43.22% 41.77% 51.31% 25.39% 27.06% 33.74% 23.09% 75.27% 16.48% 13.42% 17.86% 1.11% 48.31%     
      qoq
    5.69% 2.57% 6.38% -1.91% 12.88% 0.15% 7.22% 12.66% 18.39% -0.86% 14.43% -6.63% 19.97% 4.35% 5.32% 32.95% -20.28% 1.61% 9.44% 14.05% 16.94%  
      cost of goods sold
    12,736,000 11,983,000 12,468,000 12,050,000 13,004,000 12,526,000 10,979,000 9,308,000 9,012,000 8,577,000 7,233,000 6,076,000 6,598,000 5,538,000 5,217,000 5,488,000 5,336,000 5,250,000 4,721,000 4,170,000 3,697,000 3,339,000 
      gross profit
    38,506,000 36,501,000 34,802,000 32,385,000 32,294,000 27,605,000 29,092,000 28,066,000 24,161,000 19,444,000 21,032,000 18,625,000 19,858,000 16,515,000 15,917,000 14,579,000 9,758,000 13,683,000 13,912,000 12,856,000 11,231,000 9,427,000 
      yoy
    19.24% 32.23% 19.63% 15.39% 33.66% 41.97% 38.32% 50.69% 21.67% 17.74% 32.14% 27.75% 103.50% 20.70% 14.41% 13.40% -13.12% 45.15%     
      qoq
    5.49% 4.88% 7.46% 0.28% 16.99% -5.11% 3.66% 16.16% 24.26% -7.55% 12.92% -6.21% 20.24% 3.76% 9.18% 49.41% -28.69% -1.65% 8.21% 14.47% 19.14%  
      gross margin %
    75.15% 75.28% 73.62% 72.88% 71.29% 68.79% 72.60% 75.09% 72.83% 69.39% 74.41% 75.40% 75.06% 74.89% 75.31% 72.65% 64.65% 72.27% 74.66% 75.51% 75.23% 73.84% 
      operating expenses:
                          
      research and development
    11,883,000 10,660,000 10,064,000 10,047,000 10,780,000 10,433,000 9,200,000 8,471,000 10,655,000 8,123,000 7,499,000 6,867,000 7,261,000 5,484,000 10,039,000 4,711,000 3,393,000 3,131,000 3,264,000 3,187,000 3,113,000 2,707,000 
      selling, general and administrative
    43,818,000 40,775,000 39,110,000 36,009,000 35,830,000 34,082,000 32,522,000 28,821,000 27,700,000 27,275,000 27,595,000 25,049,000 22,549,000 21,194,000 20,872,000 19,202,000 15,758,000 19,692,000 18,156,000 17,064,000 14,135,000 13,866,000 
      total operating expenses
    55,701,000 51,435,000 49,174,000 46,056,000 46,610,000 44,515,000 41,722,000 37,292,000 38,355,000 35,398,000 35,094,000 31,916,000 29,810,000 26,678,000 30,911,000 23,913,000 19,151,000 22,823,000 21,420,000 20,251,000 17,248,000 16,573,000 
      income from operations
    -17,195,000 -14,934,000 -14,372,000 -13,671,000 -14,316,000 -16,910,000 -12,630,000 -9,226,000 -14,194,000 -15,954,000 -14,062,000 -13,291,000 -9,952,000 -10,163,000 -14,994,000 -9,334,000 -9,393,000 -9,140,000 -7,508,000 -7,395,000 -6,017,000 -7,146,000 
      yoy
    20.11% -11.69% 13.79% 48.18% 0.86% 5.99% -10.18% -30.58% 42.62% 56.98% -6.22% 42.39% 5.95% 11.19% 99.71% 26.22% 56.11% 27.90%     
      qoq
    15.14% 3.91% 5.13% -4.51% -15.34% 33.89% 36.90% -35.00% -11.03% 13.45% 5.80% 33.55% -2.08% -32.22% 60.64% -0.63% 2.77% 21.74% 1.53% 22.90% -15.80%  
      operating margin %
    -33.56% -30.80% -30.40% -30.77% -31.60% -42.14% -31.52% -24.69% -42.79% -56.94% -49.75% -53.81% -37.62% -46.08% -70.95% -46.51% -62.23% -48.28% -40.29% -43.43% -40.31% -55.98% 
      interest income
    2,321,000 2,471,000 2,618,000 2,617,000 2,434,000 2,287,000 1,776,000 617,000 122,000 12,000 15,000 42,000 47,000 95,000 153,000 249,000 299,000 404,000 441,000 565,000 598,000 52,000 
      interest expense
    -1,725,000 -1,721,000 -1,734,000 -1,732,000 -1,712,000 -1,693,000 -1,732,000 -1,714,000 -1,031,000 -621,000 -634,000 -633,000 -628,000 -623,000 -791,000 -1,215,000 -1,203,000 -1,202,000 -1,216,000 -1,176,000 -1,207,000 -1,352,000 
      other income
    -4,000 48,000 477,000 -2,000 110,000 -144,000 -28,000 4,000 -50,000 -116,000 -12,000 -3,000 -6,000 -3,000 -6,000 -15,000 -56,000 -3,000 -8,000 -1,000 -5,333,000 -15,712,000 
      net income
    -16,603,000 -14,136,000 -13,011,000 -12,788,000 -13,484,000 -16,460,000 -12,614,000 -10,319,000 -15,398,000 -16,679,000 -14,693,000 -13,885,000 -10,539,000 -10,694,000 -16,757,000 -10,315,000 -10,353,000 -9,941,000     
      yoy
    23.13% -14.12% 3.15% 23.93% -12.43% -1.31% -14.15% -25.68% 46.10% 55.97% -12.32% 34.61% 1.80% 7.57%         
      qoq
    17.45% 8.65% 1.74% -5.16% -18.08% 30.49% 22.24% -32.98% -7.68% 13.52% 5.82% 31.75% -1.45% -36.18% 62.45% -0.37% 4.14%      
      net income margin %
    -32.40% -29.16% -27.52% -28.78% -29.77% -41.02% -31.48% -27.61% -46.42% -59.52% -51.98% -56.21% -39.84% -48.49% -79.29% -51.40% -68.59% -52.51% 0% 0% 0% 0% 
      other comprehensive loss:
                          
      unrealized loss on investments
    -105,000                      
      other comprehensive income loss
    -105,000                      
      comprehensive loss
    -16,708,000 -14,225,000                     
      net income per share
    -0.42 -0.36 -0.34 -0.33 -0.35 -0.43 -0.33 -0.29 -0.44 -0.48 -0.42 -0.4 -0.31 -0.31 -0.5 -0.31 -0.32 -0.32 -0.1 -0.26 -0.42 -20.12 
      weighted-average common shares used to compute net income per share, basic and diluted
    39,620,888 39,261,496 38,804,343 38,865,011 38,765,166 38,532,202 35,775,672 35,303,958 35,143,178 35,023,297 34,635,358 34,736,015 34,534,099 34,336,433  33,757,599 32,682,360 31,338,310  30,764,354 28,458,793 1,200,719 
      other comprehensive income:
                          
      unrealized gain on investments
     -89,000 356,000 47,000       -9,500 -2,000 -3,000 -33,000 -113,000 -164,000 -126,000      
      other comprehensive income
     -89,000                     
      loss on debt extinguishment
            -245,000              
      other comprehensive loss
      -29,500 47,000 -414,000                  
      net income and comprehensive loss
      -10,712,500 -12,741,000 -13,898,000 -16,211,000 -12,589,000 -10,508,000 -15,400,000 -16,679,000 -14,694,000 -13,887,000 -10,542,000 -10,727,000 -7,614,500 -10,479,000 -10,479,000 -9,501,000 -11,031,000 -8,007,000 -11,959,000 -24,158,000 
      change in unrealized loss on investments
        -414,000                  
      change in unrealized gain on investments
         249,000 25,000 -189,000 -2,000              
      net change in other comprehensive loss
         249,000 25,000 -189,000 -2,000  -1,000 -2,000 -3,000 -33,000 -113,000 -164,000 -126,000 440,000     
      unrealized gains on investments
                     440,000     
      net income and comprehensive loss attributable to non-controlling interest
                          
      net income and comprehensive loss attributable to silk road medical, inc. common stockholders
                      -8,289,000 -8,007,000   
    Balance Sheets:
    Quarterly
    Annual
      Unit: USD2024-06-30 2024-03-31 2023-12-31 2023-09-30 2023-06-30 2023-03-31 2022-12-31 2022-09-30 2022-06-30 2022-03-31 2021-12-31 2021-09-30 2021-06-30 2021-03-31 2020-12-31 2020-09-30 2020-06-30 2020-03-31 2019-12-31 2019-09-30 2019-06-30 2019-03-31 
                            
        assets
                            
        current assets:
                            
        cash and cash equivalents
      22,639,000 22,629,000 20,210,000 29,188,000 28,400,000 50,427,000 55,358,000 51,306,000 87,637,000 93,602,000 110,231,000 105,642,000 101,849,000 94,575,000 69,466,000 62,468,000 73,442,000 27,552,000 39,181,000 112,277,000 118,247,000 15,509,000 
        short-term investments
      149,344,000 151,833,000 161,264,000 163,673,000 159,961,000 138,640,000 158,316,000 53,826,000 21,234,000   17,127,000 26,293,000 41,497,000 78,016,000 91,442,000 84,416,000 70,067,000 51,508,000    
        accounts receivable
      26,252,000 27,203,000 23,573,000 21,779,000 21,525,000 19,956,000 18,007,000 17,019,000 15,779,000 13,876,000 11,832,000 10,976,000 11,747,000 11,106,000 9,070,000 9,398,000 7,753,000 8,670,000 8,601,000 6,932,000 5,417,000 4,096,000 
        inventories
      29,682,000 30,486,000 29,876,000 22,066,000 19,067,000 17,182,000 19,293,000 20,293,000 17,616,000 17,726,000 17,851,000 16,049,000 12,771,000 11,960,000 9,989,000 10,946,000 11,621,000 12,101,000 10,322,000 9,275,000 8,963,000 8,056,000 
        prepaid expenses and other current assets
      13,104,000 3,543,000 5,912,000 4,277,000 4,543,000 4,049,000 3,924,000 4,543,000 4,653,000 2,564,000 3,412,000 4,662,000 5,877,000 4,757,000 6,787,000 3,443,000 3,863,000 1,894,000 2,878,000 3,503,000 3,249,000 1,391,000 
        total current assets
      241,021,000 235,694,000 240,835,000 240,983,000 233,496,000 230,254,000 254,898,000 146,987,000 146,919,000 127,768,000 143,326,000 154,456,000 158,537,000 163,895,000 173,328,000 177,697,000 181,095,000 120,284,000 112,490,000 131,987,000 135,876,000 29,052,000 
        long-term investments
      14,178,000 2,027,000 9,456,000 4,348,000 13,884,000 15,285,000             18,224,000    
        property and equipment
      8,381,000 8,085,000 8,114,000 8,337,000 8,644,000 8,897,000 9,372,000 9,671,000 9,755,000 9,866,000 7,697,000 5,132,000 3,428,000 2,777,000 2,844,000 2,824,000 2,885,000 2,707,000 2,734,000 2,697,000 2,743,000 2,846,000 
        other non-current assets
      6,227,000 6,508,000 6,904,000 7,196,000 7,336,000 4,996,000 5,260,000 5,731,000 5,815,000 5,134,000 5,370,000 5,711,000 5,931,000 2,680,000 2,832,000 2,997,000 3,233,000 3,444,000 3,644,000 3,575,000 3,723,000 6,460,000 
        total assets
      269,807,000 252,314,000 265,309,000 260,864,000 263,360,000 259,587,000 269,685,000 162,544,000 162,721,000 143,000,000 156,625,000 165,531,000 168,206,000 169,662,000 179,314,000 183,828,000 187,523,000 126,745,000 137,402,000 138,569,000 142,652,000 38,668,000 
        liabilities and stockholders' equity
                            
        current liabilities:
                            
        accounts payable
      3,693,000 2,966,000 5,676,000 5,094,000 5,338,000 5,272,000 2,523,000 4,312,000 3,666,000 2,926,000 2,379,000 4,908,000 1,958,000 2,923,000 2,598,000 2,046,000 2,542,000 3,194,000 1,898,000 1,965,000 1,189,000 3,134,000 
        accrued liabilities
      27,879,000 18,371,000 24,607,000 18,928,000 18,759,000 15,598,000 21,965,000 19,621,000 17,575,000 16,744,000 19,802,000 16,011,000 14,705,000 13,291,000 16,957,000 13,008,000 9,142,000 11,125,000 15,034,000 10,476,000 8,299,000 7,658,000 
        total current liabilities
      31,572,000 21,337,000 30,283,000 24,022,000 24,097,000 20,870,000 24,488,000 23,933,000 21,241,000 29,499,000 26,086,000 20,919,000 16,663,000 16,214,000 19,555,000 15,054,000 11,684,000 14,319,000 16,932,000 12,441,000 9,488,000 10,792,000 
        long-term debt
      76,147,000 75,886,000 75,626,000 75,364,000 75,104,000 74,848,000 74,596,000 74,340,000 74,033,000 38,901,000 44,786,000 48,652,000 48,614,000 48,574,000 48,533,000 45,160,000 45,066,000 44,972,000 44,879,000 44,785,000 44,690,000 44,597,000 
        other liabilities
      7,404,000 7,806,000 8,249,000 8,336,000 8,654,000 6,256,000 6,726,000 7,073,000 7,418,000 6,893,000 6,513,000 7,781,000 6,791,000 3,720,000 3,726,000 3,876,000 3,693,000 3,497,000 3,700,000 3,900,000 4,097,000 4,285,000 
        total liabilities
      115,123,000 105,029,000 114,158,000 107,722,000 107,855,000 101,974,000 105,810,000 105,346,000 102,692,000 75,293,000 77,385,000 77,352,000 72,068,000 68,508,000 71,814,000 64,090,000 60,443,000 62,788,000 65,511,000 61,126,000 58,275,000 91,477,000 
        commitments and contingencies
                            
        stockholders' equity:
                            
        preferred stock, 0.001 par value
                            
        shares authorized: 5,000,000 at june 30, 2024 and december 31, 2023
                            
        shares issued and outstanding: none at june 30, 2024 and december 31, 2023
                            
        common stock
                            
        shares authorized: 100,000,000 at june 30, 2024 and december 31, 2023
                            
        shares issued and outstanding: 40,612,481 and 39,165,481 at june 30, 2024 and december 31, 2023, respectively
      41,000                      
        additional paid-in capital
      584,959,000 560,854,000 550,495,000 539,831,000 529,453,000 517,663,000 507,715,000 388,452,000 380,775,000 373,053,000 367,907,000 362,152,000 356,224,000 350,699,000 346,318,000 341,687,000 338,550,000 264,951,000 263,384,000 260,647,000 259,574,000 5,194,000 
        accumulated other comprehensive income
      -122,000 -17,000 72,000   83,000 -166,000 -191,000 -2,000   1,000 3,000 6,000 39,000 152,000 316,000 442,000 2,000    
        accumulated deficit
      -430,194,000 -413,591,000 -399,455,000 -386,444,000 -373,656,000 -360,172,000 -343,712,000 -331,098,000 -320,779,000 -305,381,000 -288,702,000 -274,009,000 -260,124,000 -249,585,000 -238,891,000 -222,135,000 -211,820,000 -201,467,000 -191,526,000 -183,235,000 -175,228,000 -163,269,000 
        total stockholders' equity
      154,684,000 147,285,000 151,151,000 153,142,000 155,505,000 157,613,000 163,875,000 57,198,000 60,029,000 67,707,000 79,240,000 88,179,000 96,138,000 101,154,000  119,738,000 127,080,000 63,957,000  77,443,000 84,377,000  
        total liabilities and stockholders' equity
      269,807,000 252,314,000 265,309,000 260,864,000 263,360,000 259,587,000 269,685,000 162,544,000 162,721,000 143,000,000 156,625,000 165,531,000 168,206,000 169,662,000  183,828,000 187,523,000 126,745,000     
        shares authorized: 5,000,000 at march 31, 2024 and december 31, 2023
                            
        shares issued and outstanding: none at march 31, 2024 and december 31, 2023
                            
        shares authorized: 100,000,000 at march 31, 2024 and december 31, 2023
                            
        shares issued and outstanding: 39,436,634 and 39,165,481 at march 31, 2024 and december 31, 2023, respectively
       39,000                     
        restricted cash
           155,000 155,000 155,000 232,000 232,000 232,000 232,000 310,000 310,000 310,000 310,000 310,000 310,000 310,000 310,000 310,000 310,000 
        shares authorized: 5,000,000 at december 31, 2023 and 2022
                            
        shares issued and outstanding: none at december 31, 2023 and 2022
                            
        shares authorized: 100,000,000 at december 31, 2023 and 2022
                            
        shares issued and outstanding: 39,165,481 and 38,355,972 at december 31, 2023 and 2022, respectively
        39,000                    
        shares authorized: 5,000,000 at september 30, 2023 and december 31, 2022
                            
        shares issued and outstanding: none at september 30, 2023 and december 31, 2022
                            
        shares authorized: 100,000,000 at september 30, 2023 and december 31, 2022
                            
        shares issued and outstanding: 38,907,789 and 38,355,972 at september 30, 2023 and december 31, 2022, respectively
         39,000                   
        accumulated other comprehensive loss
         -284,000 -331,000                  
        shares authorized: 5,000,000 at june 30, 2023 and december 31, 2022
                            
        shares issued and outstanding: none at june 30, 2023 and december 31, 2022
                            
        shares authorized: 100,000,000 at june 30, 2023 and december 31, 2022
                            
        shares issued and outstanding: 38,812,280 and 38,355,972 at june 30, 2023 and december 31, 2022, respectively
          39,000                  
        shares authorized: 5,000,000 at march 31, 2023 and december 31, 2022
                            
        shares issued and outstanding: none at march 31, 2023 and december 31, 2022
                            
        shares authorized: 100,000,000 at march 31, 2023 and december 31, 2022
                            
        shares issued and outstanding: 38,708,441 and 38,355,972 at march 31, 2023 and december 31, 2022, respectively
           39,000                 
        short-term debt
               9,829,000 3,905,000            
        shares authorized: 5,000,000 at december 31, 2022 and 2021
                            
        shares issued and outstanding: none at december 31, 2022 and 2021
                            
        shares authorized: 100,000,000 at december 31, 2022 and 2021
                            
        shares issued and outstanding: 38,355,972 and 34,980,896 at december 31, 2022 and 2021, respectively
            38,000                
        shares authorized: 5,000,000 at september 30, 2022 and december 31, 2021
                            
        shares issued and outstanding: none at september 30, 2022 and december 31, 2021
                            
        shares authorized: 100,000,000 at september 30, 2022 and december 31, 2021
                            
        shares issued and outstanding: 35,381,085 and 34,980,896 at september 30, 2022 and december 31, 2021, respectively
             35,000               
        shares authorized: 5,000,000 at june 30, 2022 and december 31, 2021
                            
        shares issued and outstanding: none at june 30, 2022 and december 31, 2021
                            
        shares authorized: 100,000,000 at june 30, 2022 and december 31, 2021
                            
        shares issued and outstanding: 35,193,169 and 34,980,896 at june 30, 2022 and december 31, 2021, respectively
              35,000              
        shares authorized: 5,000,000 at march 31, 2022 and december 31, 2021
                            
        shares issued and outstanding: none at march 31, 2022 and december 31, 2021
                            
        shares authorized: 100,000,000 at march 31, 2022 and december 31, 2021
                            
        shares issued and outstanding: 35,073,602 and 34,980,896 at march 31, 2022 and december 31, 2021, respectively
               35,000             
        shares authorized: 5,000,000 at december 31, 2021 and 2020
                            
        shares issued and outstanding: none at december 31, 2021 and 2020
                            
        shares authorized: 100,000,000 at december 31, 2021 and 2020
                            
        shares issued and outstanding: 34,980,896 and 34,249,649 at december 31, 2021 and 2020, respectively
                35,000            
        shares authorized: 5,000,000 at september 30, 2021 and december 31, 2020
                            
        shares issued and outstanding: none at september 30, 2021 and december 31, 2020
                            
        shares authorized: 100,000,000 at september 30, 2021 and december 31, 2020
                            
        shares issued and outstanding: 34,854,822 and 34,249,649 at september 30, 2021 and december 31, 2020, respectively
                 35,000           
        shares authorized: 5,000,000 at june 30, 2021 and december 31, 2020
                            
        shares issued and outstanding: none at june 30, 2021 and december 31, 2020
                            
        shares authorized: 100,000,000 at june 30, 2021 and december 31, 2020
                            
        shares issued and outstanding: 34,623,409 and 34,249,649 at june 30, 2021 and december 31, 2020, respectively
                  35,000          
        shares authorized: 5,000,000 at march 31, 2021 and december 31, 2020
                            
        shares issued and outstanding: none at march 31, 2021 and december 31, 2020
                            
        shares authorized: 100,000,000 at march 31, 2021 and december 31, 2020
                            
        shares issued and outstanding: 34,438,290 and 34,249,649 at march 31, 2021 and december 31, 2020, respectively
                   34,000         
        liabilities and stockholders’ equity
                            
        stockholders’ equity):
                            
        shares authorized: 5,000,000 at december 31, 2020 and 2019
                            
        shares issued and outstanding: none at december 31, 2020 and 2019
                            
        shares authorized: 100,000,000 at december 31, 2020 and 2019
                            
        shares issued and outstanding: 34,249,649 and 31,255,267 at december 31, 2020 and 2019, respectively
                    34,000        
        total stockholders’ equity
                    107,500,000    71,891,000    
        total liabilities and stockholders’ equity
                    179,314,000    137,402,000    
        shares authorized: 5,000,000 at september 30, 2020 and december 31, 2019
                            
        shares issued and outstanding: none
                            
        shares authorized: 100,000,000 at september 30, 2020 and december 31, 2019
                            
        shares issued and outstanding: 33,889,077 and 31,255,267 at september 30, 2020 and december 31, 2019, respectively
                     34,000       
        shares authorized: 5,000,000 at june 30, 2020 and december 31, 2019
                            
        shares authorized: 100,000,000 at june 30, 2020 and december 31, 2019
                            
        shares issued and outstanding: 33,610,099 and 31,255,267 at june 30, 2020 and december 31, 2019, respectively
                      34,000      
        shares authorized: 5,000,000 at march 31, 2020 and december 31, 2019
                            
        shares authorized: 100,000,000 at march 31, 2020 and december 31, 2019
                            
        shares issued and outstanding: 31,395,637 and 31,255,267 at march 31, 2020 and december 31, 2019, respectively
                       31,000     
        liabilities, redeemable convertible preferred stock and stockholders’ equity
                            
        redeemable convertible preferred stock
                           31,803,000 
        shares authorized: none and 24,069,615 at december 31, 2019 and 2018, respectively
                            
        shares issued and outstanding: none and 21,233,190 at december 31, 2019 and 2018, respectively
                            
        liquidation preference: none and 121,144 at december 31, 2019 and 2018, respectively
                            
        stockholders’ equity
                            
        shares authorized: 5,000,000 and none at december 31, 2019 and 2018, respectively
                            
        shares issued and outstanding: none at december 31, 2019 and 2018
                            
        shares authorized: 100,000,000 and 29,879,220 at december 31, 2019 and 2018, respectively
                            
        shares issued and outstanding: 31,255,267 and 1,135,310 at december 31, 2019 and 2018, respectively
                        31,000    
        liabilities, redeemable convertible preferred stock and stockholders' equity
                            
        shares authorized: none and 24,069,615 at september 30, 2019 and december 31, 2018, respectively
                            
        shares issued and outstanding: none and 21,233,190 at september 30, 2019 and december 31, 2018, respectively
                            
        liquidation preference: none and 121,144 at september 30, 2019 and december 31, 2018, respectively
                            
        stockholders' equity
                            
        shares authorized: 5,000,000 and none at september 30, 2019 and december 31, 2018, respectively
                            
        shares authorized: 100,000,000 and 29,879,220 at september 30, 2019 and december 31, 2018, respectively
                            
        shares issued and outstanding: 30,775,980 and 1,135,310 at september 30, 2019 and december 31, 2018, respectively
                         31,000   
        total liabilities, redeemable convertible preferred stock and stockholders' equity
                         138,569,000 142,652,000  
        shares authorized: none and 24,069,615 at june 30, 2019 and december 31, 2018, respectively
                            
        shares issued and outstanding: none and 21,233,190 at june 30, 2019 and december 31, 2018, respectively
                            
        liquidation preference: none and 121,144 at june 30, 2019 and december 31, 2018, respectively
                            
        shares authorized: 5,000,000 and none at june 30, 2019 and december 31, 2018, respectively
                            
        shares authorized: 100,000,000 and 29,879,220 at june 30, 2019 and december 31, 2018, respectively
                            
        shares issued and outstanding: 30,747,714 and 1,135,310 at june 30, 2019 and december 31, 2018, respectively
                          31,000  
        liabilities, redeemable convertible preferred stock and stockholders' deficit
                            
        shares authorized: 24,069,615 at march 31, 2019 and december 31, 2018
                            
        shares issued and outstanding: 21,238,105 and 21,233,190 at march 31, 2019 and december 31, 2018, respectively
                            
        liquidation preference: 121,174 and 121,144 at march 31, 2019 and december 31, 2018, respectively
                           105,265,000 
        stockholders' deficit:
                            
        shares authorized: 29,879,220 at march 31, 2019 and december 31, 2018
                            
        shares issued and outstanding: 1,386,615 and 1,135,310 at march 31, 2019 and december 31, 2018, respectively
                           1,000 
        total stockholders' deficit
                           -158,074,000 
        total liabilities, redeemable convertible preferred stock and stockholders' deficit
                           38,668,000 
      Cashflow Statements:
      Quarterly
      Annual
        Unit: USD2024-06-30 2024-03-31 2023-12-31 2023-09-30 2023-06-30 2023-03-31 2022-12-31 2022-09-30 2022-06-30 2022-03-31 2021-12-31 2021-09-30 2021-06-30 2021-03-31 2020-12-31 2020-09-30 2020-06-30 2020-03-31 2019-12-31 2019-09-30 2019-06-30 2019-03-31 
                              
          cash flows from operating activities
                              
          net income
        -16,603,000 -14,136,000 -13,011,000 -12,788,000 -13,484,000 -16,460,000 -12,614,000 -10,319,000 -15,398,000 -16,679,000 -14,693,000 -13,885,000 -10,539,000 -10,694,000 -16,757,000 -10,314,000 -10,353,000 -9,941,000 -8,291,000 -8,007,000 -11,959,000 -24,158,000 
          adjustments to reconcile net income to net cash from operating activities:
                              
          depreciation and amortization expense
        665,000 644,000 656,000 656,000 685,000 699,000 662,000 543,000 502,000 420,000 309,000 241,000 243,000 239,000 226,000 195,000 184,000 184,000 182,000 180,000 176,000 174,000 
          stock-based compensation expense
        11,040,000 10,359,000 9,609,000 10,247,000 10,199,000 8,838,000 7,545,000 6,339,000 6,161,000 4,978,000 3,984,000 3,686,000 3,409,000 3,533,000 2,273,000 2,006,000 1,654,000 1,293,000 954,000 924,000 837,000 262,000 
          accretion of discounts on investments
        -1,045,000 -1,359,000  -1,918,000                   
          amortization of debt discount and debt issuance costs
        58,000 59,000 59,000 59,000 57,000 57,000 58,000 69,000 52,000 39,000 39,000 39,000 39,000 41,000 31,000 12,000 11,000 12,000 12,000 12,000 11,000 11,000 
          amortization of right-of-use asset
        288,000 281,000 275,000 269,000 271,000 281,000 275,000 270,000 254,000 242,000 260,000 254,000 215,000 158,000 155,000 152,000 149,000 146,000 142,000 140,000 138,000 162,000 
          non-cash interest expense
        187,000 222,000 219,000 201,000 181,000 218,000 214,000 349,000    200,000   -8,000 82,000 84,000 83,000 77,000 40,000 84,000 471,000 
          loss on disposal of property and equipment
          16,000 144,000 5,000 55,000 120,000     1,000       
          benefit from doubtful accounts receivable
                              
          benefit from excess and obsolete inventories
        171,000 175,000 175,000 9,000 13,000 1,000 1,000 8,000 5,000 -8,000 21,000 6,000 26,000 24,000 8,000 4,000 13,000 92,000 40,000 35,000 16,000 27,000 
          changes in assets and liabilities:
                              
          accounts receivable
        951,000 -3,630,000 -1,794,000 -279,000 -1,569,000 -1,968,000 -988,000 -1,240,000 -1,906,000 -2,038,000 -863,000 771,000 -641,000 -2,036,000 334,000 -1,628,000 917,000 -60,000 1,334,000 -1,953,000 -1,732,000 110,000 
          inventories
        633,000 -785,000 -7,985,000 -3,009,000 -1,896,000 2,109,000 999,000 -2,685,000 105,000 134,000 -1,819,000 -3,288,000 1,334,000 -1,790,000 -1,429,000 672,000 467,000 -1,871,000 -1,087,000 -347,000 -923,000 -2,339,000 
          prepaid expenses and other current assets
        -9,561,000 2,369,000 -1,635,000 266,000 -495,000 -124,000 607,000 110,000 -2,089,000 847,000 1,242,000 1,213,000 -3,810,000 583,000 815,000 421,000 -1,969,000 983,000 625,000 -255,000 -1,857,000 16,000 
          other assets
        -7,000 115,000 17,000 -129,000 -107,000 -17,000 25,000 -15,000 -32,000 -5,000 -10,000 -33,000 -68,000 -6,000 10,000 83,000 62,000 55,000 -212,000 8,000 1,407,000 -651,000 
          accounts payable
        719,000 -2,937,000 586,000 -258,000 67,000 2,668,000 -698,000 589,000 1,057,000 19,000 -2,463,000 2,137,000 -1,051,000 218,000 563,000 -233,000 -1,012,000 1,274,000 -97,000 757,000 -2,332,000 2,287,000 
          accrued liabilities
        9,524,000 -6,256,000 5,662,000 169,000 3,411,000 -6,388,000 2,612,000 1,876,000 548,000 -3,168,000 3,789,000 1,111,000 1,941,000 -2,423,000 2,200,000 3,871,000 -2,013,000 -3,912,000 2,709,000 1,878,000 325,000 52,000 
          other liabilities
        -403,000 -443,000 -85,000 -319,000 -340,000 -471,000 -346,000 -346,000 -378,000 380,000 -1,176,000 989,000 -328,000 -5,000 -150,000 183,000 196,000 -203,000 -200,000 -197,000 697,000 -1,069,000 
          net cash from operating activities
        -3,383,000 -15,322,000 -8,453,000 -6,798,000 -4,616,000 -12,147,000 -2,724,000 -4,726,000 -10,406,000 -14,725,000 -11,432,000 -6,495,000 -9,036,000 -11,972,000 -14,269,000 -4,423,000 -11,581,000 -11,795,000 -5,261,000 -6,346,000 -9,383,000 -8,620,000 
          capital expenditures
        -946,000 -161,000 -457,000 -318,000 -436,000 -229,000 -1,626,000 -318,000 -1,510,000 -1,434,000 -2,912,000 -117,000 -630,000 39,000 -10,000 -90,000 -267,000 -112,000 23,000 -129,000 -15,000 -95,000 
          free cash flows
        -4,329,000 -15,483,000 -8,910,000 -7,116,000 -5,052,000 -12,376,000 -4,350,000 -5,044,000 -11,916,000 -16,159,000 -14,344,000 -6,612,000 -9,666,000 -11,933,000 -14,279,000 -4,513,000 -11,848,000 -11,907,000 -5,238,000 -6,475,000 -9,398,000 -8,715,000 
          cash flows from investing activities
                              
          purchases of property and equipment
        -954,000 -388,000 -453,000 -333,000 -434,000 -287,000 -1,567,000 -389,000 -977,000 -2,072,000 -2,752,000 -1,132,000 -807,000 -67,000  -108,000 -345,000 -134,000  -131,000   
          purchases of investments
        -71,595,000 -43,871,000 -26,127,000 -34,711,000 -87,724,000 -26,407,000 -114,484,000 -32,506,000       -21,022,000 -35,278,000 -21,632,000 -1,974,000     
          proceeds from maturity of investments
        62,875,000 62,000,000 25,000,000 42,500,000 69,000,000 32,800,000     17,000,000 9,100,000 15,000,000 36,300,000 34,175,000 28,000,000 7,180,000 2,000,000     
          net cash from investing activities
        -9,674,000 17,741,000 -1,580,000 7,456,000 -19,158,000 6,106,000 -104,951,000 -32,895,000 -22,150,000 -2,072,000 14,250,000 7,968,000 14,193,000 36,233,000 12,898,000 -7,386,000 -14,797,000 -108,000 -69,619,000 -131,000 -89,000 -117,000 
          cash flows from financing activities
                              
          proceeds from issuance of common stock
          1,055,000 130,000 1,592,000 1,110,000 2,729,000 1,338,000 1,561,000 168,000 1,739,000 2,242,000 2,117,000 848,000 2,359,000 1,130,000 1,405,000 274,000 1,784,000 68,000 363,000 375,000 
          net cash from financing activities
          1,055,000 130,000 1,592,000 1,110,000 111,727,000 1,213,000 26,591,000 168,000 1,771,000 2,242,000 2,117,000 848,000 8,369,000 835,000 72,268,000 274,000 1,784,000 507,000 112,210,000 -744,000 
          net change in cash and cash equivalents
                              
          cash and cash equivalents, beginning of period
                              
          cash and cash equivalents, end of period
                              
          supplemental disclosure of cash flow information
                              
          cash paid for interest
        1,479,000 1,440,000 1,457,000 1,472,000 1,474,000 1,418,000 1,460,000 1,296,000 505,000 582,000 789,000 394,000 595,000 582,000 4,581,000 1,120,000 1,108,000 1,108,000 1,127,000 1,125,000 1,112,000 870,000 
          noncash investing and financing activities:
                              
          accounts payable and accrued liabilities for purchases of property and equipment
        8,000 227,000 -4,000 15,000 -2,000 58,000 -59,000 71,000 -533,000 638,000 -160,000 1,015,000 177,000 106,000 -10,000 18,000 78,000 22,000 23,000 2,000 -15,000 22,000 
          right-of-use asset obtained in exchange for lease obligation
              -91,000       3,982,000 
          net change in cash, cash equivalents and restricted cash
         2,419,000 -8,978,000 788,000 -22,182,000 -4,931,000 4,052,000 -36,408,000 -5,965,000 -16,629,000 4,589,000 3,715,000 7,274,000 25,109,000 6,998,000 -10,974,000 45,890,000 -11,629,000 -73,096,000 -5,970,000 102,738,000 -9,481,000 
          cash, cash equivalents and restricted cash, beginning of period
         20,210,000  55,513,000  110,463,000  69,776,000  39,491,000  25,300,000 
          cash, cash equivalents and restricted cash, end of period
         22,629,000  788,000 -22,182,000 50,582,000  -36,408,000 -5,965,000 93,834,000  3,715,000 7,274,000 94,885,000  -10,974,000 45,890,000 27,862,000  -5,970,000 102,738,000 15,819,000 
          amortization of premiums (accretion of discounts) on investments
             -1,753,000 -1,081,000 -274,000       159,000 88,000       
          loss on extinguishment of debt
                            
          benefit from (recovery of) doubtful accounts receivable
                              
          changes in operating assets and liabilities:
                              
          proceeds from sale of property and equipment
                              
          proceeds from public offerings, net of underwriting discount, commissions and offering costs paid
                      -295,000       
          proceeds from long-term debt
              -1,089,000               
          principal repayment of long-term debt
                              
          proceeds from disgorgement of short-swing profits
                              
          cash, cash equivalents and restricted cash, beginning of year
                              
          cash, cash equivalents and restricted cash, end of year
                              
          change in accounts receivable allowances
           26,000 19,000                 
          principal repayment of debt
                             
          payments of debt issuance costs
               -116,000               
          payments of deferred offering costs
                             -1,149,000 
          unpaid debt issuance costs
               -116,000               
          unpaid deferred offering costs
                             1,204,000 
          change in benefit from doubtful accounts receivable
              3,000 -6,000     -6,000 -17,000 -9,000     
          repayment of interest paid in kind
                              
          payments of prepayment penalty and lender fees
                              
          amortization of premiums on investments
                   64,000 201,000 186,000         
          change in fair value of redeemable convertible preferred stock warrant liability
                          5,318,000 15,712,000 
          proceeds from exercise of redeemable convertible preferred stock warrants
                            
          proceeds from exercise of common stock warrants
                            
          net exercise of convertible preferred stock warrants to preferred stock
                             
          conversion of convertible preferred stock to common stock upon initial public offering
                             
          offering costs in accrued liabilities
                              
          changes in assets and liabilities
                              
          purchase of property and equipment
                             -117,000 
          non-controlling interest
                              
          non-cash investing and financing activities:
                              
          landlord paid tenant improvements
                              
          net exercise of redeemable convertible preferred stock warrants to preferred stock
                              
          conversion of redeemable convertible preferred stock to common stock upon initial public offering
                              
          offering costs in accounts payable and accrued liabilities
                       -295,000       
          amortization of premium on investments
                         79,000     
          payment of deferred offering costs
                              
          accretion of discount on investments
                              
          proceeds from initial public offering, net of underwriting discount, commissions and offering costs paid
                          439,000   
          benefit from sales returns and allowances
                              
          benefit from accounts receivable allowances
                            411,000 313,000 
          proceeds from exercise of preferred stock warrants
                             30,000