MRCY short interest
Mercury Systems · settlement of Oct 30, 2026
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As of Oct 30, 2026, 5.4M MRCY shares were sold short, down 2.2% from the Oct 15, 2026 count. At the stock's average daily volume, that is 8.4 days to cover.
Mercury Systems research · MRCY trades by Congress · Short interest movers · Most shorted stocks · Source
- Shares sold short
- 5.4M5,434,784
- Change
- −2.2%from 5.6M
- Of shares outstanding
- 8.92%#837 of 3,540 stocks measured
- Days to cover
- 8.4at the average daily volume
- Average daily volume
- 648,814shares, as FINRA reports it
- Most in 16 settlements
- 5.6MOct 15, 2026
Every settlement
16 settlements, newest first| Settlement | Shares short | Change | Avg daily volume | Days to cover |
|---|---|---|---|---|
| Oct 30, 2026 | 5,434,784 | −2.2% | 648,814 | 8.4 |
| Oct 15, 2026 | 5,556,601 | +10.8% | 444,626 | 13 |
| Sep 30, 2026 | 5,013,538 | −0.4% | 678,670 | 7.4 |
| Sep 15, 2026 | 5,032,343 | −3.8% | 689,379 | 7.3 |
| Aug 31, 2026 | 5,231,532 | +5.1% | 1,068,941 | 4.9 |
| Aug 14, 2026 | 4,979,217 | +0.5% | 479,785 | 10 |
| Jul 31, 2026 | 4,952,067 | +3.0% | 625,141 | 7.9 |
| Jul 15, 2026 | 4,805,548 | +3.6% | 564,196 | 8.5 |
| Jun 30, 2026 | 4,639,605 | +1.5% | 981,202 | 4.7 |
| Jun 15, 2026 | 4,572,200 | −3.4% | 741,680 | 6.2 |
| May 29, 2026 | 4,733,680 | −2.7% | 612,397 | 7.7 |
| May 15, 2026 | 4,865,616 | +2.5% | 629,258 | 7.7 |
| Apr 30, 2026 | 4,746,107 | +1.6% | 502,983 | 9.4 |
| Apr 15, 2026 | 4,672,746 | +5.0% | 434,123 | 11 |
| Mar 31, 2026 | 4,450,059 | +10.4% | 695,330 | 6.4 |
| Mar 13, 2026 | 4,029,807 | — | 623,995 | 6.5 |
Short seller alerts · MRCY · free
Get an email when Mercury Systems moves
An email when FINRA publishes its short interest, when it files to sell shares, and when its borrow fee passes 10%, 25%, 50% or more a year.
Short seller alerts for MRCY: an email when its short interest is published, when it files to sell shares and when its borrow fee passes 10%, 25%, 50% or more a year. Unsubscribe in one click.
Cost to borrow
Read 3:50 PM ET, Nov 11, 2026Borrowing MRCY to sell short costs 0.27% a year at Interactive Brokers, which has 1,300,000 shares left to lend. The hardest stocks to borrow.
Filings to sell shares
SEC filings since Jun 9, 2026No filing by MRCY to sell shares in the SEC’s filings from Jun 9, 2026 to Nov 10, 2026. Every company that filed.
Fails to deliver
SEC files to Oct 14, 2026| Settlement date | Shares failing | Price | Value |
|---|---|---|---|
| Oct 8, 2026 | 1,598 | $79.75 | $127K |
| Sep 23, 2026 | 13,535 | $83.88 | $1.1M |
| Sep 21, 2026 | 6,250 | $85.28 | $533K |
| Sep 15, 2026 | 54 | $81.03 | $4K |
| Sep 10, 2026 | 187 | $80.76 | $15K |
| Sep 4, 2026 | 20 | $84.71 | $2K |
| Aug 28, 2026 | 6 | $90.47 | $543 |
| Aug 27, 2026 | 10,429 | $89.76 | $936K |
| Aug 24, 2026 | 11 | $91.36 | $1K |
| Aug 21, 2026 | 302 | $94.23 | $28K |
| Aug 19, 2026 | 51 | $105.00 | $5K |
| Aug 14, 2026 | 101 | $109.79 | $11K |
| Aug 13, 2026 | 1,000 | $111.64 | $112K |
| Aug 11, 2026 | 66 | $108.64 | $7K |
| Aug 7, 2026 | 19,046 | $108.83 | $2.1M |
No fails reported for MRCY after Oct 8, 2026; the SEC’s files run to Oct 14, 2026.
Source
Short interest is the number of shares sold short and not yet bought back. Brokers report it to FINRA for two settlement dates a month, the middle and the end, and FINRA publishes each count about a week later. It is not a daily figure: between settlements no one publishes a count. Days to cover is the short interest divided by the average daily volume FINRA reports beside it. A rising count is shown in red and a falling one in green.
Fails to deliver are the shares sellers had not delivered by the settlement date, a balance outstanding on each date, from the SEC’s fails-to-deliver files, published twice a month about two weeks after each half-month ends. The value is the shares times that day’s closing price in the same file. Every security’s fails.
The cost to borrow is Interactive Brokers’ own yearly fee to borrow the stock and the shares it has left to lend, from the file it publishes about every 15 minutes; a weekday’s last read stands for that day. It is one broker’s figure; another’s can differ. The hardest stocks to borrow.
Filings to sell shares are the company’s prospectuses for shares, shelf and other registrations, and 8-Ks reporting a private sale, from the SEC’s daily index of filings, each cover read so that bond offerings are left out. Each form links to the filing. Every listed company that filed.