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HowShorted

How shorted was Masimo Corporation? MASI

Masimo Corporation left the US market in 2026. This page is a frozen archive of its reported short interest, ending 29 May 2026. The ticker MASI no longer refers to this company and may since have been reassigned.
6.69%
of shares outstanding reported short · settlement date 29 May 2026
vs previous report
−0.43
5 reports (~10 weeks)
+1.55
days to cover
3.65
Aggregate net short position time series for Masimo Corporation

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 Masimo Corporation 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
12 Jan 20267.31% 31 Dec 20257.69% 15 Jan 2026+0.38
4 Nov 20257.10% 31 Oct 20257.12% 14 Nov 2025+0.02
5 Aug 20256.02% 31 Jul 20257.56% 15 Aug 2025+1.54
6 May 20254.76% 30 Apr 20255.59% 15 May 2025+0.83
25 Feb 20255.57% 14 Feb 20256.25% 28 Feb 2025+0.68
16 Jan 20255.27% 15 Jan 20255.40% 31 Jan 2025+0.13
5 Nov 20246.25% 31 Oct 20246.24% 15 Nov 2024−0.01
29 Oct 20246.69% 15 Oct 20246.25% 31 Oct 2024−0.44
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Sector: Healthcare

History

Full reported short interest history
Settlement dateShort %Change
29 May 20266.69%−0.43
15 May 20267.12%−0.30
30 Apr 20267.42%+0.13
15 Apr 20267.29%+1.07
31 Mar 20266.22%+1.08
13 Mar 20265.14%−2.19
27 Feb 20267.33%−0.30
13 Feb 20267.63%−0.03
30 Jan 20267.66%−0.03
15 Jan 20267.69%+0.38
31 Dec 20257.31%−0.08
15 Dec 20257.39%+0.28
28 Nov 20257.11%−0.01
14 Nov 20257.12%+0.02
31 Oct 20257.10%−0.07
15 Oct 20257.17%+0.08
30 Sep 20257.09%+0.24
15 Sep 20256.85%+0.34
29 Aug 20256.51%−1.05
15 Aug 20257.56%+1.54
31 Jul 20256.02%+0.04
15 Jul 20255.98%+0.40
30 Jun 20255.58%−0.47
13 Jun 20256.05%+0.28
30 May 20255.77%+0.18
15 May 20255.59%+0.83
30 Apr 20254.76%−0.39
15 Apr 20255.15%−0.20
31 Mar 20255.35%−0.87
14 Mar 20256.22%−0.03
28 Feb 20256.25%+0.68
14 Feb 20255.57%+0.17
31 Jan 20255.40%+0.13
15 Jan 20255.27%+0.15
31 Dec 20245.12%−1.32
13 Dec 20246.44%+0.46
29 Nov 20245.98%−0.26
15 Nov 20246.24%−0.01
31 Oct 20246.25%−0.44
15 Oct 20246.69%+0.21
30 Sep 20246.48%+0.98
13 Sep 20245.50%−1.89
30 Aug 20247.39%−5.31
15 Aug 202412.70%+3.84
31 Jul 20248.86%+4.00
15 Jul 20244.86%−0.16
28 Jun 20245.02%−7.22
14 Jun 202412.24%+3.04
31 May 20249.20%+3.40
15 May 20245.80%−1.53
30 Apr 20247.33%−0.28
15 Apr 20247.61%−0.38
28 Mar 20247.99%−0.81
15 Mar 20248.80%−0.18
29 Feb 20248.98%−0.68
15 Feb 20249.66%+0.32
31 Jan 20249.34%+0.71
12 Jan 20248.63%+0.34
29 Dec 20238.29%−0.14
15 Dec 20238.43%−0.08
30 Nov 20238.51%+0.65
15 Nov 20237.86%+0.51
31 Oct 20237.35%−0.20
13 Oct 20237.55%0.00
29 Sep 20237.55%+0.14
15 Sep 20237.41%+0.77
31 Aug 20236.64%−0.33
15 Aug 20236.97%+0.44
31 Jul 20236.53%+1.67
14 Jul 20234.86%+0.04
30 Jun 20234.82%+0.10
15 Jun 20234.72%+1.15
31 May 20233.57%+1.55
15 May 20232.02%+0.38
28 Apr 20231.64%+0.02
14 Apr 20231.62%+0.22
31 Mar 20231.40%−0.30
15 Mar 20231.70%+0.01
28 Feb 20231.69%−0.12
15 Feb 20231.81%−0.34
31 Jan 20232.15%−0.64
13 Jan 20232.79%−0.13
30 Dec 20222.92%−0.79
15 Dec 20223.71%−0.55
30 Nov 20224.26%−0.75
15 Nov 20225.01%−0.53
31 Oct 20225.54%−0.32
14 Oct 20225.86%−0.67
30 Sep 20226.53%+0.27
15 Sep 20226.26%−0.30
31 Aug 20226.56%−1.25
15 Aug 20227.81%+1.09
29 Jul 20226.72%+1.21
15 Jul 20225.51%+0.65
30 Jun 20224.86%−0.15
15 Jun 20225.01%−1.09
31 May 20226.10%+0.08
13 May 20226.02%+1.85
29 Apr 20224.17%+0.20
14 Apr 20223.97%+1.25
31 Mar 20222.72%+1.07
15 Mar 20221.65%+0.33
28 Feb 20221.32%−1.11
15 Feb 20222.43%+0.05
31 Jan 20222.38%−0.45
14 Jan 20222.83%+0.41
31 Dec 20212.42%−0.27
15 Dec 20212.69%−0.18
30 Nov 20212.87%−0.06
15 Nov 20212.93%+0.27
29 Oct 20212.66%−0.21
15 Oct 20212.87%−0.05
30 Sep 20212.92%+0.31
15 Sep 20212.61%−0.24
31 Aug 20212.85%−0.13
13 Aug 20212.98%+0.01
30 Jul 20212.97%+0.25
15 Jul 20212.72%+0.27
30 Jun 20212.45%+0.17
15 Jun 20212.28%−0.07
28 May 20212.35%+0.14
14 May 20212.21%+0.52
30 Apr 20211.69%+0.28
15 Apr 20211.41%−0.19
31 Mar 20211.60%−0.15
15 Mar 20211.75%0.00
26 Feb 20211.75%+0.15
12 Feb 20211.60%−0.02
29 Jan 20211.62%−0.25
15 Jan 20211.87%−0.08
31 Dec 20201.95%−0.04
15 Dec 20201.99%−0.34
30 Nov 20202.33%+0.17
13 Nov 20202.16%−0.09
30 Oct 20202.25%−0.17
15 Oct 20202.42%−0.05
30 Sep 20202.47%+0.23
15 Sep 20202.24%−0.02
31 Aug 20202.26%−0.03
14 Aug 20202.29%+0.14
31 Jul 20202.15%+0.47
15 Jul 20201.68%−0.78
30 Jun 20202.46%−0.67
15 Jun 20203.13%+0.33
29 May 20202.80%+0.48
15 May 20202.32%−0.44
30 Apr 20202.76%+0.52
15 Apr 20202.24%+0.10
31 Mar 20202.14%−0.16
13 Mar 20202.30%+0.53
28 Feb 20201.77%+0.11
14 Feb 20201.66%−0.18
31 Jan 20201.84%−0.02
15 Jan 20201.86%−0.99
31 Dec 20192.85%+1.78
13 Dec 20191.07%−0.22
29 Nov 20191.29%−0.22
15 Nov 20191.51%−0.23
31 Oct 20191.74%+0.22
15 Oct 20191.52%−0.09
30 Sep 20191.61%+0.29
13 Sep 20191.32%−0.13
30 Aug 20191.45%−0.04
15 Aug 20191.49%−0.03
31 Jul 20191.52%+0.17
15 Jul 20191.35%−0.27
28 Jun 20191.62%−0.41
14 Jun 20192.03%+0.48
31 May 20191.55%−0.23
15 May 20191.78%−0.17
30 Apr 20191.95%−0.34
15 Apr 20192.29%−0.09
29 Mar 20192.38%−0.16
15 Mar 20192.54%+0.40
28 Feb 20192.14%−0.15
15 Feb 20192.29%+0.25
31 Jan 20192.04%−0.12
15 Jan 20192.16%−0.05
31 Dec 20182.21%+0.15
14 Dec 20182.06%−0.29
30 Nov 20182.35%−0.29
15 Nov 20182.64%+0.48
31 Oct 20182.16%−0.04
15 Oct 20182.20%−0.15
28 Sep 20182.35%+0.21
14 Sep 20182.14%−0.01
31 Aug 20182.15%−0.44
15 Aug 20182.59%+0.10
31 Jul 20182.49%−0.19
13 Jul 20182.68%+1.11
29 Jun 20181.57%−0.36
15 Jun 20181.93%−0.41
31 May 20182.34%−0.49
15 May 20182.83%−0.05
30 Apr 20182.88%−0.23
13 Apr 20183.11%+0.03
29 Mar 20183.08%+0.25
15 Mar 20182.83%+0.69
28 Feb 20182.14%−0.36
15 Feb 20182.50%+0.62
31 Jan 20181.88%+0.18
12 Jan 20181.70%−0.60
29 Dec 20172.30%–

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

Frequently asked questions

How shorted was Masimo Corporation?
Masimo Corporation left the US market in 2026. Its final reported figure was 6.69% of shares outstanding for settlement date 29 May 2026, 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 MASI'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 MASI's days to cover?
3.65 days for settlement date 29 May 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.