Castellum, Inc. (CTM) — Short Interest & Borrow Fee
Data as of April 30, 2026.
Castellum, Inc. (CTM) has 4.19M shares sold short as of the latest FINRA settlement report on April 30, 2026.
Short interest has decreased by 4.91% compared with the prior settlement.
At the current average daily volume, covering all open short positions would take about 6.55 days (days to cover).
The borrow fee to short CTM is currently 1.51%. That is 2.2% above the 7-day average.
finshort's Short Pressure Score is 55 of 100, indicating moderate squeeze potential based on days-to-cover, borrow fee, and short-volume momentum.
Insider Confidence Score: 34 (based on 3-month SEC Form 4 filings).
Key short-selling metrics for CTM
- Short Interest
- 4,187,834 shares
- Short % of Float
- 5.63%
- Days to Cover
- 6.55
- Cost to Borrow
- 1.51%
- Shortable Shares
- 400,000
- Short Pressure Score
- 55 / 100
- Market Cap
- $63,921,785
- Float
- 74,353,322
- Institutional Ownership
- 11.61%
- Insider Ownership
- 20.90%
Recent short-interest history for CTM
| Settlement date | Short interest | Change | Days to cover |
|---|---|---|---|
| Apr 30, 2026 | 4,187,834 | -4.91% | 6.55 |
| Apr 15, 2026 | 4,403,986 | -8.26% | 5.15 |
| Mar 31, 2026 | 4,800,688 | 4.44% | 2.89 |
| Mar 13, 2026 | 4,596,457 | 19.55% | 6.43 |
| Feb 27, 2026 | 3,844,921 | 1.41% | 4.23 |
| Feb 13, 2026 | 3,791,646 | 4.80% | 3.29 |
| Jan 30, 2026 | 3,617,871 | 44.47% | 2.44 |
| Jan 15, 2026 | 2,504,221 | 3.33% | 1.32 |
| Dec 31, 2025 | 2,423,431 | 4.82% | 1.04 |
| Dec 15, 2025 | 2,311,915 | -46.25% | 1.36 |
Frequently asked questions
- What is the current short interest in CTM?
- As of the latest FINRA settlement dated April 30, 2026, CTM had approximately 4,187,834 shares sold short. Short interest data is reported by FINRA twice per month.
- How much does it cost to short CTM?
- The latest borrow fee (cost to borrow) for CTM is 1.51% per year, based on IBKR data. Fees can change throughout the trading day as shares are borrowed and returned.
- What are CTM's days to cover?
- Days to cover for CTM is approximately 6.55 days. This estimates how many trading days it would take short sellers to buy back all outstanding short shares at the current average daily volume.
- Where does finshort get CTM short data?
- Short interest and short volume come directly from FINRA. Cost-to-borrow data is sourced from Interactive Brokers (IBKR). Insider and institutional ownership data come from SEC EDGAR filings (Form 4, 13F, 13D/G). All data is refreshed multiple times daily.
- How often is CTM short data updated?
- FINRA short interest settles twice monthly and is published several business days later. Short volume is published daily after market close. Cost-to-borrow rates are refreshed throughout each trading session. Institutional 13F filings are quarterly; insider Form 4 filings are typically within two business days of a transaction.