Skip to content
HowShorted

How shorted is PACIFIC BIOSCIENCES OF CALIFORNIA, INC.? PACB

#268most shorted US stockof 3,805 ranked stocks, more shorted than 92%

15.73%
of shares outstanding reported short · settlement date 15 Sep 2026
vs previous report
−0.22
5 reports (~10 weeks)
+0.44
days to cover
10.49
Aggregate net short position time series for PACIFIC BIOSCIENCES OF CALIFORNIA, INC.

Markers along the chart's base: ▲ results announced (an 8-K reporting results was filed) ▲ quarterly or annual report filed. Dates are SEC filing dates; hover a point to see events since the previous settlement.

Days to cover

FINRA's own figure: reported shares short divided by the stock's average daily trading volume, published alongside each settlement. It expresses the short position in days of typical trading rather than as a percentage of the company; the two can move differently.

Aggregate net short position time series for PACIFIC BIOSCIENCES OF CALIFORNIA, INC. days to cover

Short interest around results

For each results announcement (an 8-K reporting results, by its SEC filing date), the FINRA settlement before it and the first one after. Settlements fall twice a month, so the two figures can sit up to a month apart and much else changes in between: this shows what was reported, not why.

Reported short interest before and after each results announcement
Results filedSettlement beforeSettlement afterChange
5 Aug 202615.77% 31 Jul 202617.18% 14 Aug 2026+1.41
7 May 202615.16% 30 Apr 202619.29% 15 May 2026+4.13
12 Feb 202611.79% 30 Jan 202612.89% 13 Feb 2026+1.10
12 Jan 202611.26% 31 Dec 202511.62% 15 Jan 2026+0.36
5 Nov 202510.77% 31 Oct 202511.12% 14 Nov 2025+0.35
7 Aug 202513.94% 31 Jul 202514.04% 15 Aug 2025+0.10
8 May 202516.40% 30 Apr 202518.98% 15 May 2025+2.58
9 Apr 202519.94% 31 Mar 202517.23% 15 Apr 2025−2.71

Fails to deliver

The SEC's fails-to-deliver figure for PACB: the aggregate net balance of shares that failed to be delivered at each settlement date, published by the SEC twice a month and shown here verbatim for the trailing window. A balance is not a daily flow, and a fail has many ordinary causes; the SEC says it cannot guarantee the accuracy of the data. See what fails to deliver are and the largest balances today.

Last balance on file
4,275
8 Sep 2026
Highest in window
1,921,473
14 Oct 2025
Days with a balance
104
Window
16 Sep 2025 to 14 Sep 2026
Aggregate net short position time series for PACIFIC BIOSCIENCES OF CALIFORNIA, INC. fails to deliver

Source: U.S. Securities and Exchange Commission, fails-to-deliver data (public domain). Only settlement days with a positive balance appear; the largest balance in the window was 1.9M shares.

Embed this chart

Paste this snippet to embed the interactive chart. It updates with each FINRA report and keeps the source attribution. Preview

Download chart cardShare on XRedditLinkedIn
Cite this page
Plain
Wikipedia
BibTeX

Sector: Healthcare · By year: 2018 · 2019 · 2020 · 2021 · 2022 · 2023 · 2024 · 2025 · 2026

History

Full reported short interest history
Settlement dateShort %Change
15 Sep 202615.73%−0.22
31 Aug 202615.95%−1.23
14 Aug 202617.18%+1.41
31 Jul 202615.77%+0.88
15 Jul 202614.89%−0.40
30 Jun 202615.29%−4.21
15 Jun 202619.50%+3.82
29 May 202615.68%−3.61
15 May 202619.29%+4.13
30 Apr 202615.16%−0.19
15 Apr 202615.35%+0.24
31 Mar 202615.11%+1.41
13 Mar 202613.70%+1.05
27 Feb 202612.65%−0.24
13 Feb 202612.89%+1.10
30 Jan 202611.79%+0.17
15 Jan 202611.62%+0.36
31 Dec 202511.26%−0.09
15 Dec 202511.35%+0.07
28 Nov 202511.28%+0.16
14 Nov 202511.12%+0.35
31 Oct 202510.77%−0.72
15 Oct 202511.49%−1.15
30 Sep 202512.64%−2.52
15 Sep 202515.16%+2.80
29 Aug 202512.36%−1.68
15 Aug 202514.04%+0.10
31 Jul 202513.94%−0.85
15 Jul 202514.79%−0.99
30 Jun 202515.78%+2.57
13 Jun 202513.21%−4.12
30 May 202517.33%−1.65
15 May 202518.98%+2.58
30 Apr 202516.40%−0.83
15 Apr 202517.23%−2.71
31 Mar 202519.94%+0.44
14 Mar 202519.50%−3.13
28 Feb 202522.63%−1.72
14 Feb 202524.35%+2.30
31 Jan 202522.05%−0.06
15 Jan 202522.11%+1.35
31 Dec 202420.76%+1.39
13 Dec 202419.37%−0.49
29 Nov 202419.86%+0.82
15 Nov 202419.04%+0.63
31 Oct 202418.41%+0.60
15 Oct 202417.81%−1.14
30 Sep 202418.95%+1.88
13 Sep 202417.07%−5.32
30 Aug 202422.39%+0.39
15 Aug 202422.00%+1.05
31 Jul 202420.95%−1.70
15 Jul 202422.65%+1.92
28 Jun 202420.73%+0.69
14 Jun 202420.04%+0.12
31 May 202419.92%−0.85
15 May 202420.77%+1.38
30 Apr 202419.39%+1.28
15 Apr 202418.11%−0.20
28 Mar 202418.31%+1.30
15 Mar 202417.01%+0.76
29 Feb 202416.25%+1.18
15 Feb 202415.07%+2.31
31 Jan 202412.76%−0.70
12 Jan 202413.46%−0.67
29 Dec 202314.13%+1.08
15 Dec 202313.05%+0.55
30 Nov 202312.50%−2.17
15 Nov 202314.67%+1.54
31 Oct 202313.13%−1.93
13 Oct 202315.06%+1.86
29 Sep 202313.20%−0.30
15 Sep 202313.50%+0.31
31 Aug 202313.19%+0.66
15 Aug 202312.53%+1.20
31 Jul 202311.33%−0.96
14 Jul 202312.29%−0.33
30 Jun 202312.62%+2.54
15 Jun 202310.08%−0.10
31 May 202310.18%+0.51
15 May 20239.67%−0.63
28 Apr 202310.30%−0.70
14 Apr 202311.00%+0.84
31 Mar 202310.16%−0.48
15 Mar 202310.64%+1.32
28 Feb 20239.32%+0.72
15 Feb 20238.60%−0.50
31 Jan 20239.10%−1.60
13 Jan 202310.70%−0.21
30 Dec 202210.91%+0.82
15 Dec 202210.09%+0.36
30 Nov 20229.73%−0.97
15 Nov 202210.70%+0.42
31 Oct 202210.28%−0.37
14 Oct 202210.65%−0.60
30 Sep 202211.25%−2.23
15 Sep 202213.48%+0.61
31 Aug 202212.87%−1.68
15 Aug 202214.55%−1.21
29 Jul 202215.76%−0.30
15 Jul 202216.06%−2.22
30 Jun 202218.28%+1.34
15 Jun 202216.94%+1.62
31 May 202215.32%+0.45
13 May 202214.87%−0.03
29 Apr 202214.90%+1.21
14 Apr 202213.69%−0.40
31 Mar 202214.09%+0.18
15 Mar 202213.91%+0.48
28 Feb 202213.43%+1.04
15 Feb 202212.39%+0.37
31 Jan 202212.02%+2.21
14 Jan 20229.81%+0.78
31 Dec 20219.03%−0.14
15 Dec 20219.17%+1.48
30 Nov 20217.69%−0.42
15 Nov 20218.11%−0.80
29 Oct 20218.91%+1.11
15 Oct 20217.80%+0.67
30 Sep 20217.13%+0.60
15 Sep 20216.53%+0.15
31 Aug 20216.38%+0.52
13 Aug 20215.86%−0.14
30 Jul 20216.00%−0.16
15 Jul 20216.16%−0.72
30 Jun 20216.88%−0.06
15 Jun 20216.94%+0.06
28 May 20216.88%−0.19
14 May 20217.07%+0.21
30 Apr 20216.86%+0.78
15 Apr 20216.08%−0.59
31 Mar 20216.67%+0.73
15 Mar 20215.94%+1.33
26 Feb 20214.61%−0.42
12 Feb 20215.03%−2.18
29 Jan 20217.21%−0.09
15 Jan 20217.30%−1.36
31 Dec 20208.66%+2.04
15 Dec 20206.62%−0.98
30 Nov 20207.60%−0.41
13 Nov 20208.01%−1.70
30 Oct 20209.71%−1.57
15 Oct 202011.28%+0.02
30 Sep 202011.26%+0.10
15 Sep 202011.16%+0.41
31 Aug 202010.75%−0.54
14 Aug 202011.29%+0.02
31 Jul 202011.27%−0.30
15 Jul 202011.57%−0.02
30 Jun 202011.59%+1.16
15 Jun 202010.43%−0.13
29 May 202010.56%−0.18
15 May 202010.74%−0.87
30 Apr 202011.61%−0.18
15 Apr 202011.79%−0.19
31 Mar 202011.98%−1.91
13 Mar 202013.89%+2.23
28 Feb 202011.66%+1.02
14 Feb 202010.64%−0.60
31 Jan 202011.24%−1.75
15 Jan 202012.99%−0.33
31 Dec 201913.32%+0.93
13 Dec 201912.39%−0.68
29 Nov 201913.07%−0.22
15 Nov 201913.29%+0.17
31 Oct 201913.12%+0.87
15 Oct 201912.25%−0.56
30 Sep 201912.81%−0.47
13 Sep 201913.28%+0.42
30 Aug 201912.86%+0.21
15 Aug 201912.65%−0.75
31 Jul 201913.40%−1.76
15 Jul 201915.16%−0.74
28 Jun 201915.90%+1.58
14 Jun 201914.32%+0.42
31 May 201913.90%+0.52
15 May 201913.38%−0.79
30 Apr 201914.17%−0.69
15 Apr 201914.86%+0.85
29 Mar 201914.01%+0.35
15 Mar 201913.66%+0.36
28 Feb 201913.30%+2.55
15 Feb 201910.75%+0.95
31 Jan 20199.80%+0.50
15 Jan 20199.30%+0.91
31 Dec 20188.39%+0.72
14 Dec 20187.67%+0.84
30 Nov 20186.83%+0.25
15 Nov 20186.58%+0.14
31 Oct 20186.44%−0.36
15 Oct 20186.80%0.00
28 Sep 20186.80%+0.63
14 Sep 20186.17%−0.96
31 Aug 20187.13%+0.04
15 Aug 20187.09%−0.17
31 Jul 20187.26%−0.63
13 Jul 20187.89%−0.20
29 Jun 20188.09%+0.53
15 Jun 20187.56%−0.30
31 May 20187.86%−0.59
15 May 20188.45%−0.12
30 Apr 20188.57%−1.11
13 Apr 20189.68%+0.67
29 Mar 20189.01%−2.16
15 Mar 201811.17%+1.08
28 Feb 201810.09%−1.22
15 Feb 201811.31%+1.84
31 Jan 20189.47%−0.39
12 Jan 20189.86%+0.33
29 Dec 20179.53%–

Newest first. Scroll inside the table for earlier dates, back to 29 Dec 2017.

Frequently asked questions

How shorted is PACIFIC BIOSCIENCES OF CALIFORNIA, INC. right now?
15.73% of PACIFIC BIOSCIENCES OF CALIFORNIA, INC.'s (PACB) shares outstanding were reported short for settlement date 15 Sep 2026, per FINRA's consolidated short interest report. That makes it the 268th most shorted US stock, out of 3,805 we rank.
What does this number include?
FINRA member firms must report their short positions in all US equities twice a month; FINRA consolidates them per security. We divide that official share count by the company's shares outstanding from its SEC filings. This is the regulatory figure, not a daily estimate.
Why does it only update twice a month?
US short interest is reported for settlement on the 15th and the last business day of each month, and FINRA publishes the consolidated figures about nine business days later. That cadence is set by regulation; no daily official figure exists.
Is this PACB's short float?
No. This is short interest as a percentage of shares outstanding, the count in the company's SEC filings. "Short float" divides the same FINRA short count by the public float, which excludes closely held shares, so it comes out higher for the same company. We publish no float estimates: the float is not a regulatory figure.
What is PACB's days to cover?
10.49 days for settlement date 15 Sep 2026: FINRA's own short interest ratio, the reported shares short divided by average daily trading volume. It is published in the same FINRA file and shown verbatim; we hold no volume data ourselves.
Which funds are short?
US public short interest is aggregate-only: individual short sellers are not named. Only some EU markets publish named positions.