Ticker

MASI

Masimo Corporation - Common Stock (MASI)

Get an email when MASI is filed on. A free account follows up to three names.Create a free account →

MASI in the last 90 days

Masimo Corporation - Common Stock (MASI) (MASI) had no congress transactions and no insider purchases in filings from the last 90 days.

FINRA’s latest report (settlement 29 MAY 2026) shows 3,501,739 shares held short, 3.6 days to cover, down 6.1% from the report before.

  • Delay: each filing below shows how many days passed between the trade and its publication. None of this is real-time.

Latest filing on file: 16 OCT 2025 · FINRA settlement 29 MAY 2026 · public filings, reported as filed

FINRA short interest

Settlement 29 MAY 2026 · shares held short

3,501,739shares held short

Days to cover

3.65

Avg daily volume

958,552

Since last report

-6.13%

As of 29 May 2026, 3,501,739 Masimo Corporation - Common Stock (MASI) shares were held short — the total across every reporting firm, not one fund's position. That is 228,535 shares fewer than the previous report, a 6.13% decrease. At the average daily volume of 958,552 shares, that position represents 3.65 days of trading — what the filing calls days to cover.

This is the most recent figure that exists, and it is 126 days old. FINRA collects short interest twice a month, on a settlement date, and publishes it about eight business days later. So nobody has a live short-interest number for MASI — not us, and not anyone quoting one. We print the settlement date on the figure so you always know which day you are looking at.

Across the 12 reports we hold, the position has fallen from 3,968,788 shares on 15 December 2025 to 3,501,739 today, a change of 11.8%. The highest reading in that window was 4,129,092 shares on 15 January 2026.

SettlementShares shortDays to cover
29 MAY 20263,501,7393.65
15 MAY 20263,730,2744.28
30 APR 20263,884,4726.06
15 APR 20263,818,9255.47
31 MAR 20263,248,0481.68
13 MAR 20262,680,8851.45
27 FEB 20263,828,1351.00
13 FEB 20263,982,2206.15
30 JAN 20264,112,2565.16
15 JAN 20264,129,0925.50
31 DEC 20253,926,7505.52
15 DEC 20253,968,7884.83
What is MASI's short interest?
3,501,739 shares, as of the 29 May 2026 settlement date. That is the figure FINRA published, unadjusted.
What percentage of the float is short?
We do not publish that, because FINRA does not publish float. The regulator reports the number of shares held short; turning it into a percentage needs a share count from somewhere else, and different sources disagree about what counts as float. We would rather give you the number that was actually filed than a percentage built on an assumption.
How current is this?
It is 126 days old, and that is as fresh as short interest gets. FINRA measures it twice a month and publishes it seven business days after the settlement date. Any site showing you a "live" short interest figure is showing you something else.
What does days to cover mean?
It is the short position divided by average daily trading volume — here, 3.65. It describes how many days of ordinary trading the position is equivalent to. It is arithmetic from the filing, not a prediction about what will happen.
Where does this come from?
FINRA's consolidated short interest file, which is public. We read it directly and store it unchanged, except that we blank the days-to-cover placeholder FINRA writes when a stock has almost no volume.

Disclosed insider buying on file

—no purchase on file passed the price check

Open-market purchases only — the amount is a fact, not a verdict.

On file here

Short positions0

Insider purchases0

Congress transactions1

Latest change16 OCT 2025

SHORT POSITIONS · 0INSIDER BUYS · 0CONGRESS · 1

Congress transactions on file

1 disclosed · newest first · every row links to its filing

WhoAmount as filedTradedFiledLag
Hon. Kevin HernSOLD$15,001 – $50,00026 SEPT 202516 OCT 202520 days
What this page will never showNo price targetsNo score out of 100No buy or sell callsNo predictionsDocuments, dates, and how late they were.