MASI Short Volume
Masimo Corporation (MASI) operates in the Healthcare sector, specifically the Medical - Instruments & Supplies industry, with a market capitalization near $9.34B, listed on NASDAQ, employing roughly 3,600 people, carrying a beta of 1.13 to the broader market. Masimo Corporation develops, manufactures, and markets noninvasive monitoring technologies and hospital automation solutions worldwide. Led by Catherine Szyman, public since 2007-08-08.
Short volume measures the number of shares sold short on a given day as reported by FINRA. Tracking short volume relative to total volume helps identify unusual bearish sentiment or short-squeeze potential.
- Latest Date
- 2026-05-15
- Short Volume
- 45.7K
- Total Volume
- 172.5K
- Short %
- 26.48%
- 30-Day Avg Short %
- 37.32%
Showing 30 days of FINRA short volume data for Masimo Corporation.
Learn how short volume is reported and how to read the data →
MASI most-active contracts
| Type | Strike | Expiration | Volume | OI | IV | Bid | Ask |
|---|---|---|---|---|---|---|---|
| CALL | $175.00 | Jun 18, 2026 | 0 | 254 | 156.4% | $3.70 | $5.80 |
| CALL | $180.00 | Jan 15, 2027 | 0 | 979 | 2.9% | $0.10 | $1.00 |
| CALL | $175.00 | Sep 18, 2026 | 0 | 536 | 6.3% | $4.50 | $5.00 |
| CALL | $175.00 | Dec 18, 2026 | 1 | 658 | 3.0% | $4.80 | $7.50 |
Top 4 contracts from the ORATS-sourced nightly scan; ranked by volume within the broader S&P 500/400/600 + ETF universe.
Frequently asked MASI short volume questions
- What is the daily MASI short volume?
- As of May 15, 2026, Masimo Corporation (MASI) short volume is 45.7K shares against 172.5K total reported volume, or 26.48% short-side. Short volume measures shares sold short during the day; it is flow, not inventory.
- How is MASI short volume reported?
- FINRA publishes the Daily Short Sale Volume File for trades reported to FINRA TRFs and the FINRA/Nasdaq ADF on a T+1 basis. The headline figure is the count of shares that printed at the short-sale or short-exempt tick across all reporting venues for the symbol; each exchange separately publishes its own daily short-sale data file.
- What does MASI short volume tell options traders?
- Daily short-sale flow is one input that helps disambiguate dealer-hedging activity from directional bear flow when the chain shows fresh customer call inventory. It is not a clean MM-only proxy: the headline number mixes directional shorting, options-MM delta-hedging, ETF-creation arbitrage, and convertible-arb hedging. Cross-check against gamma-exposure and OI changes for a cleaner read.