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 IMGN'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 IMGN's days to cover?

5.00 days for settlement date 31 Jan 2024: 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.

How shorted was ImmunoGen, Inc.? IMGN

ImmunoGen, Inc. left the US market in 2024. This page is a frozen archive of its reported short interest, ending 31 Jan 2024. The ticker IMGN no longer refers to this company and may since have been reassigned.

7.74%

of shares outstanding reported short · settlement date 31 Jan 2024

vs previous report: +0.66
5 reports (~10 weeks): −4.53
days to cover: 5.00

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.

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 filed	Settlement before	Settlement after	Change
2 Nov 2023	9.40% 31 Oct 2023	12.27% 15 Nov 2023	+2.87
31 Jul 2023	7.13% 14 Jul 2023	7.48% 15 Aug 2023	+0.35
28 Apr 2023	11.11% 14 Apr 2023	6.89% 15 May 2023	−4.22
1 Mar 2023	10.33% 28 Feb 2023	11.32% 15 Mar 2023	+0.99
9 Jan 2023	8.17% 30 Dec 2022	8.13% 13 Jan 2023	−0.04
4 Nov 2022	8.03% 31 Oct 2022	7.51% 15 Nov 2022	−0.52
29 Jul 2022	6.74% 15 Jul 2022	6.48% 15 Aug 2022	−0.26
6 May 2022	8.36% 29 Apr 2022	8.64% 13 May 2022	+0.28

Embed this chart

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

<iframe src="https://howshorted.com/embed/us/imgn-2024/" width="100%" height="430" style="border:0" loading="lazy" title="ImmunoGen, Inc. short interest chart"></iframe>
<p>Source: FINRA data compiled by <a href="https://howshorted.com/us/company/imgn-2024/">howshorted.com</a></p>

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Plain

Short position data for ImmunoGen, Inc.: FINRA, compiled by howshorted.com, settlement date 31 Jan 2024. https://howshorted.com/us/company/imgn-2024/

Wikipedia

<ref>{{cite web |title=ImmunoGen, Inc. short position data |url=https://howshorted.com/us/company/imgn-2024/ |website=HowShorted |publisher=howshorted.com (data: FINRA) |date=2024-01-31 |access-date=2026-10-13}}</ref>

BibTeX

@misc{howshorted-immunogen-inc-2024-01-31,
  title        = {ImmunoGen, Inc. short position data},
  author       = {{HowShorted}},
  howpublished = {\url{https://howshorted.com/us/company/imgn-2024/}},
  note         = {Data: FINRA, settlement date 31 Jan 2024; accessed 2026-10-13},
  year         = {2024}
}

Sector: Healthcare

History

Full reported short interest history
Settlement date	Short %	Change
31 Jan 2024	7.74%	+0.66
12 Jan 2024	7.08%	−0.67
29 Dec 2023	7.75%	+0.41
15 Dec 2023	7.34%	−6.98
30 Nov 2023	14.32%	+2.05
15 Nov 2023	12.27%	+2.87
31 Oct 2023	9.40%	−0.59
13 Oct 2023	9.99%	+1.30
29 Sep 2023	8.69%	+1.14
15 Sep 2023	7.55%	−0.12
31 Aug 2023	7.67%	+0.19
15 Aug 2023	7.48%	+0.55
31 Jul 2023	6.93%	−0.20
14 Jul 2023	7.13%	−0.27
30 Jun 2023	7.40%	−1.81
15 Jun 2023	9.21%	+1.34
31 May 2023	7.87%	+0.98
15 May 2023	6.89%	−3.33
28 Apr 2023	10.22%	−0.89
14 Apr 2023	11.11%	−0.79
31 Mar 2023	11.90%	+0.58
15 Mar 2023	11.32%	+0.99
28 Feb 2023	10.33%	+1.81
15 Feb 2023	8.52%	+0.47
31 Jan 2023	8.05%	−0.08
13 Jan 2023	8.13%	−0.04
30 Dec 2022	8.17%	+1.30
15 Dec 2022	6.87%	−0.53
30 Nov 2022	7.40%	−0.11
15 Nov 2022	7.51%	−0.52
31 Oct 2022	8.03%	+1.39
14 Oct 2022	6.64%	+0.42
30 Sep 2022	6.22%	+0.72
15 Sep 2022	5.50%	−0.08
31 Aug 2022	5.58%	−0.90
15 Aug 2022	6.48%	−0.83
29 Jul 2022	7.31%	+0.57
15 Jul 2022	6.74%	−0.39
30 Jun 2022	7.13%	−0.14
15 Jun 2022	7.27%	+0.06
31 May 2022	7.21%	−1.43
13 May 2022	8.64%	+0.28
29 Apr 2022	8.36%	+1.10
14 Apr 2022	7.26%	−0.81
31 Mar 2022	8.07%	+0.14
15 Mar 2022	7.93%	+0.50
28 Feb 2022	7.43%	+1.03
15 Feb 2022	6.40%	+0.08
31 Jan 2022	6.32%	−0.15
14 Jan 2022	6.47%	+0.04
31 Dec 2021	6.43%	+1.32
15 Dec 2021	5.11%	+0.92
30 Nov 2021	4.19%	−0.96
15 Nov 2021	5.15%	−2.85
29 Oct 2021	8.00%	−0.64
15 Oct 2021	8.64%	−0.91
30 Sep 2021	9.55%	−0.93
15 Sep 2021	10.48%	−0.12
31 Aug 2021	10.60%	+0.52
13 Aug 2021	10.08%	−0.21
30 Jul 2021	10.29%	+0.15
15 Jul 2021	10.14%	−0.92
30 Jun 2021	11.06%	−0.48
15 Jun 2021	11.54%	+1.17
28 May 2021	10.37%	−0.06
14 May 2021	10.43%	−0.02
30 Apr 2021	10.45%	−0.66
15 Apr 2021	11.11%	−0.81
31 Mar 2021	11.92%	+0.02
15 Mar 2021	11.90%	−0.31
26 Feb 2021	12.21%	−1.99
12 Feb 2021	14.20%	−0.18
29 Jan 2021	14.38%	+0.44
15 Jan 2021	13.94%	−0.58
31 Dec 2020	14.52%	+2.37
15 Dec 2020	12.15%	+1.17
30 Nov 2020	10.98%	−0.34
13 Nov 2020	11.32%	+1.34
30 Oct 2020	9.98%	+0.79
15 Oct 2020	9.19%	−0.75
30 Sep 2020	9.94%	+0.94
15 Sep 2020	9.00%	−1.01
31 Aug 2020	10.01%	−0.10
14 Aug 2020	10.11%	−0.07
31 Jul 2020	10.18%	+0.89
15 Jul 2020	9.29%	−0.16
30 Jun 2020	9.45%	+2.61
15 Jun 2020	6.84%	−0.09
29 May 2020	6.93%	−0.42
15 May 2020	7.35%	+0.40
30 Apr 2020	6.95%	−0.50
15 Apr 2020	7.45%	−2.30
31 Mar 2020	9.75%	+0.44
13 Mar 2020	9.31%	+2.60
28 Feb 2020	6.71%	+0.29
14 Feb 2020	6.42%	−0.39
31 Jan 2020	6.81%	+0.78
15 Jan 2020	6.03%	−2.36
31 Dec 2019	8.39%	+1.05
13 Dec 2019	7.34%	+1.66
29 Nov 2019	5.68%	+0.45
15 Nov 2019	5.23%	+0.43
31 Oct 2019	4.80%	+0.03
15 Oct 2019	4.77%	+0.21
30 Sep 2019	4.56%	+1.32
13 Sep 2019	3.24%	+0.01
30 Aug 2019	3.23%	−0.12
15 Aug 2019	3.35%	−0.23
31 Jul 2019	3.58%	−1.05
15 Jul 2019	4.63%	−0.14
28 Jun 2019	4.77%	−2.51
14 Jun 2019	7.28%	−0.14
31 May 2019	7.42%	−0.77
15 May 2019	8.19%	−0.41
30 Apr 2019	8.60%	−0.50
15 Apr 2019	9.10%	−0.17
29 Mar 2019	9.27%	+1.80
15 Mar 2019	7.47%	−0.11
28 Feb 2019	7.58%	−0.81
15 Feb 2019	8.39%	−1.34
31 Jan 2019	9.73%	−1.17
15 Jan 2019	10.90%	+1.84
31 Dec 2018	9.06%	+0.54
14 Dec 2018	8.52%	−1.01
30 Nov 2018	9.53%	−0.40
15 Nov 2018	9.93%	+0.08
31 Oct 2018	9.85%	−0.29
15 Oct 2018	10.14%	+0.36
28 Sep 2018	9.78%	+0.31
14 Sep 2018	9.47%	−0.16
31 Aug 2018	9.63%	−0.37
15 Aug 2018	10.00%	−0.53
31 Jul 2018	10.53%	−1.67
13 Jul 2018	12.20%	+0.54
29 Jun 2018	11.66%	+1.60
15 Jun 2018	10.06%	+0.58
31 May 2018	9.48%	−0.49
15 May 2018	9.97%	−0.23
30 Apr 2018	10.20%	+0.35
13 Apr 2018	9.85%	+1.50
29 Mar 2018	8.35%	−1.96
15 Mar 2018	10.31%	+0.23
28 Feb 2018	10.08%	−0.24
15 Feb 2018	10.32%	+0.21
31 Jan 2018	10.11%	+0.97
12 Jan 2018	9.14%	+0.24
29 Dec 2017	8.90%	–

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

Frequently asked questions

How shorted was ImmunoGen, Inc.?: ImmunoGen, Inc. left the US market in 2024. Its final reported figure was 7.74% of shares outstanding for settlement date 31 Jan 2024, per FINRA's consolidated short interest report; this page preserves its full history.
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 IMGN'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 IMGN's days to cover?: 5.00 days for settlement date 31 Jan 2024: 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.