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HowShorted

How shorted was MERRIMACK PHARMACEUTICALS INC? MACK

MERRIMACK PHARMACEUTICALS INC left the US market in 2024. This page is a frozen archive of its reported short interest, ending 15 May 2024. The ticker MACK no longer refers to this company and may since have been reassigned.
5.93%
of shares outstanding reported short · settlement date 15 May 2024
vs previous report
+0.13
5 reports (~10 weeks)
+0.52
days to cover
1.86
Aggregate net short position time series for MERRIMACK PHARMACEUTICALS 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 MERRIMACK PHARMACEUTICALS 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
10 May 20192.11% 30 Apr 20191.92% 15 May 2019−0.19
6 Mar 20192.50% 28 Feb 20192.30% 15 Mar 2019−0.20
7 Nov 20184.00% 31 Oct 20183.79% 15 Nov 2018−0.21
7 Aug 20186.82% 31 Jul 20186.18% 15 Aug 2018−0.64
8 May 201812.55% 30 Apr 201812.34% 15 May 2018−0.21
12 Mar 201811.89% 28 Feb 201812.14% 15 Mar 2018+0.25
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Sector: Healthcare

History

Full reported short interest history
Settlement dateShort %Change
15 May 20245.93%+0.13
30 Apr 20245.80%+0.19
15 Apr 20245.61%+0.64
28 Mar 20244.97%−0.05
15 Mar 20245.02%−0.39
29 Feb 20245.41%−0.34
15 Feb 20245.75%+0.42
31 Jan 20245.33%+0.08
12 Jan 20245.25%−0.21
29 Dec 20235.46%−0.63
15 Dec 20236.09%−0.22
30 Nov 20236.31%−0.12
15 Nov 20236.43%−0.04
31 Oct 20236.47%−0.17
13 Oct 20236.64%−0.24
29 Sep 20236.88%−0.41
15 Sep 20237.29%−0.21
31 Aug 20237.50%−0.15
15 Aug 20237.65%+0.05
31 Jul 20237.60%+0.34
14 Jul 20237.26%+0.34
30 Jun 20236.92%+1.92
15 Jun 20235.00%+0.20
31 May 20234.80%−0.25
15 May 20235.05%−0.49
28 Apr 20235.54%−0.81
14 Apr 20236.35%+0.40
31 Mar 20235.95%−0.32
15 Mar 20236.27%−0.73
28 Feb 20237.00%−0.19
15 Feb 20237.19%+0.25
31 Jan 20236.94%+0.70
13 Jan 20236.24%+0.24
30 Dec 20226.00%+2.27
15 Dec 20223.73%−1.12
30 Nov 20224.85%−1.45
15 Nov 20226.30%+4.37
31 Oct 20221.93%+0.02
14 Oct 20221.91%−0.02
30 Sep 20221.93%+0.04
15 Sep 20221.89%−0.06
31 Aug 20221.95%+0.02
15 Aug 20221.93%−0.01
29 Jul 20221.94%−0.04
15 Jul 20221.98%−0.02
30 Jun 20222.00%−0.17
15 Jun 20222.17%+0.07
31 May 20222.10%+0.07
13 May 20222.03%−0.03
29 Apr 20222.06%+0.04
14 Apr 20222.02%−0.30
31 Mar 20222.32%−0.06
15 Mar 20222.38%−0.01
28 Feb 20222.39%−1.06
15 Feb 20223.45%−0.36
31 Jan 20223.81%+0.14
14 Jan 20223.67%+0.38
31 Dec 20213.29%+0.69
15 Dec 20212.60%−0.05
30 Nov 20212.65%−0.02
15 Nov 20212.67%+0.11
29 Oct 20212.56%−0.04
15 Oct 20212.60%+0.04
30 Sep 20212.56%−0.05
15 Sep 20212.61%+0.16
31 Aug 20212.45%−0.05
13 Aug 20212.50%−0.03
30 Jul 20212.53%+0.02
15 Jul 20212.51%−0.09
30 Jun 20212.60%+0.08
15 Jun 20212.52%+0.05
28 May 20212.47%+0.02
14 May 20212.45%−0.03
30 Apr 20212.48%−0.28
15 Apr 20212.76%+0.02
31 Mar 20212.74%−0.66
15 Mar 20213.40%−0.91
26 Feb 20214.31%−0.10
12 Feb 20214.41%+0.33
29 Jan 20214.08%−0.11
15 Jan 20214.19%0.00
31 Dec 20204.19%−2.62
15 Dec 20206.81%+1.91
30 Nov 20204.90%+0.94
13 Nov 20203.96%+0.24
30 Oct 20203.72%+0.11
15 Oct 20203.61%−0.11
30 Sep 20203.72%−0.13
15 Sep 20203.85%−0.11
31 Aug 20203.96%+0.01
14 Aug 20203.95%−0.03
31 Jul 20203.98%+0.02
15 Jul 20203.96%+0.30
30 Jun 20203.66%+0.04
15 Jun 20203.62%−0.06
29 May 20203.68%−0.17
15 May 20203.85%−0.14
30 Apr 20203.99%+0.14
15 Apr 20203.85%+0.31
31 Mar 20203.54%−0.05
13 Mar 20203.59%−0.10
28 Feb 20203.69%+0.08
14 Feb 20203.61%−0.06
31 Jan 20203.67%−0.08
15 Jan 20203.75%−0.24
31 Dec 20193.99%−0.30
13 Dec 20194.29%+0.27
29 Nov 20194.02%−0.39
15 Nov 20194.41%−0.17
31 Oct 20194.58%+0.06
15 Oct 20194.52%+0.14
30 Sep 20194.38%−0.25
13 Sep 20194.63%+0.13
30 Aug 20194.50%+0.01
15 Aug 20194.49%+0.25
31 Jul 20194.24%+0.15
15 Jul 20194.09%−0.20
28 Jun 20194.29%+2.27
14 Jun 20192.02%+0.09
31 May 20191.93%+0.01
15 May 20191.92%−0.19
30 Apr 20192.11%−0.27
15 Apr 20192.38%+0.10
29 Mar 20192.28%−0.02
15 Mar 20192.30%−0.20
28 Feb 20192.50%−0.22
15 Feb 20192.72%−0.58
31 Jan 20193.30%+0.11
15 Jan 20193.19%−0.34
31 Dec 20183.53%+0.09
14 Dec 20183.44%−0.03
30 Nov 20183.47%−0.32
15 Nov 20183.79%−0.21
31 Oct 20184.00%−0.28
15 Oct 20184.28%+0.02
28 Sep 20184.26%−0.89
14 Sep 20185.15%−0.32
31 Aug 20185.47%−0.71
15 Aug 20186.18%−0.64
31 Jul 20186.82%+0.03
13 Jul 20186.79%−0.33
29 Jun 20187.12%−3.77
15 Jun 201810.89%+0.60
31 May 201810.29%−2.05
15 May 201812.34%−0.21
30 Apr 201812.55%+0.09
13 Apr 201812.46%+0.44
29 Mar 201812.02%−0.12
15 Mar 201812.14%+0.25
28 Feb 201811.89%−1.00
15 Feb 201812.89%−0.57
31 Jan 201813.46%−1.28
12 Jan 201814.74%+0.73
29 Dec 201714.01%–

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

Frequently asked questions

How shorted was MERRIMACK PHARMACEUTICALS INC?
MERRIMACK PHARMACEUTICALS INC left the US market in 2024. Its final reported figure was 5.93% of shares outstanding for settlement date 15 May 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 MACK'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 MACK's days to cover?
1.86 days for settlement date 15 May 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.