Acorn Energy, Inc. (ACFN) Ownership
ACFN ownership summary
as of October 18, 2026- Institutions
- 15.3% of shares outstanding
- Insiders
- 29.32% of shares outstanding
- Shares outstanding
- 2.5M
- Float
- 1.6M shares available to trade
- Short interest
- 1.94% 33K shares short
- Days to cover
- 0.47 short interest up 6.7% vs prior month
- Institutions 15.31%
- Insiders 29.32%
- Other investors 55.37%
ACFN top institutional holders
18 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard Capital Management, LLC | 1.50% | 38K | $696,192 | +340 (+0.9%) | June 30, 2026 |
| 2 | Geode Capital Management, LLC | 0.72% | 18K | $333,019 | +259 (+1.4%) | June 30, 2026 |
| 3 | Citadel Advisors Llc | 0.64% | 16K | $299,164 | +16,321 (0.0%) | June 30, 2026 |
| 4 | Bridgeway Capital Management, LLC | 0.49% | 12K | $229,125 | +12,500 (0.0%) | June 30, 2026 |
| 5 | Mink Brook Asset Management LLC | 0.39% | 10K | $183,300 | — | June 30, 2026 |
| 6 | Vanguard Fiduciary Trust Co | 0.33% | 8,428 | $154,485 | +60 (+0.7%) | June 30, 2026 |
| 7 | BlackRock Inc | 0.21% | 5,403 | $99,037 | +5,403 (0.0%) | June 30, 2026 |
| 8 | Access Investment Management LLC | 0.05% | 1,200 | $21,996 | — | June 30, 2026 |
| 9 | Advisor Group Holdings, Inc. | 0.01% | 351 | $6,434 | −1,545 (−81.5%) | June 30, 2026 |
| 10 | Tower Research Capital LLC | 0.01% | 327 | $5,994 | +157 (+92.4%) | June 30, 2026 |
| 11 | NATIONAL BANK OF CANADA /FI/ | 0.01% | 245 | $4,491 | — | June 30, 2026 |
| 12 | Federation des caisses Desjardins du Quebec | <0.01% | 25 | $458 | — | June 30, 2026 |
| 13 | Western Wealth Management, LLC | <0.01% | 2 | $37 | +2 (0.0%) | March 31, 2026 |
| 14 | Susquehanna International Group, LLP | 0.00% | — | — | −11,400 (−100.0%) | March 31, 2026 |
| 15 | Wells Fargo & Co | 0.00% | — | — | — | June 30, 2026 |
| 16 | UBS Group AG | 0.00% | — | — | −693 (−100.0%) | June 30, 2026 |
| 17 | Morgan Stanley - Brokerage Accounts | 0.00% | — | — | −2,312 (−100.0%) | March 31, 2026 |
| 18 | Bank of America Corp | 0.00% | — | — | −14 (−100.0%) | March 31, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 18, 8 holders added 35K shares and 5 cut 16K.
ACFN top mutual fund and ETF holders
7 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard MStar Total Stk Mkt Idx Invest | 0.85% | 22K | $396,240 | — | August 31, 2026 |
| 2 | Fidelity Extended Market Index | 0.31% | 7,900 | $144,807 | −42 (−0.5%) | August 31, 2026 |
| 3 | iShares Micro-Cap ETF | 0.19% | 4,846 | $88,827 | −33 (−0.7%) | September 30, 2026 |
| 4 | Fidelity Total Market Index | 0.10% | 2,653 | $48,629 | — | August 31, 2026 |
| 5 | Fidelity Series Total Market Index | 0.09% | 2,332 | $42,746 | — | August 31, 2026 |
| 6 | Fidelity Nasdaq Composite Index | 0.07% | 1,741 | $31,913 | — | August 31, 2026 |
| 7 | 1290 VT Micro Cap K | 0.01% | 326 | $5,976 | — | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
ACFN shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns ACFN
Institutional investors own 15.3% of Acorn Energy's shares and insiders 29.32%. The largest holder is Vanguard Capital Management, LLC with 1.50% of the shares (38K), as of June 30, 2026. Among the top 18 institutions, 8 added shares and 5 reduced their stake in the latest filings. Short interest is 1.94% of the float, or 0.47 days of average trading volume. The share count rose 63.6% since 2014.
Related: ACFN key metrics. See the ACFN stock overview for the latest quote and news.
ACFN ownership FAQ
Who owns the most Acorn Energy stock?
The largest shareholders of Acorn Energy are Vanguard Capital Management, LLC (1.50%), Geode Capital Management, LLC (0.72%), Citadel Advisors Llc (0.64%), Bridgeway Capital Management, LLC (0.49%), Mink Brook Asset Management LLC (0.39%).
What percentage of Acorn Energy is owned by institutions?
Institutions hold 15.3% of Acorn Energy's shares outstanding; insiders hold 29.32%.
Which funds own Acorn Energy?
The largest fund holders of Acorn Energy are Vanguard MStar Total Stk Mkt Idx Invest (0.85%), Fidelity Extended Market Index (0.31%), iShares Micro-Cap ETF (0.19%), Fidelity Total Market Index (0.10%), Fidelity Series Total Market Index (0.09%).
What is Acorn Energy's short interest?
33K shares of Acorn Energy were sold short, 1.94% of the float; at the average daily volume it would take 0.47 days to cover.
How many shares of Acorn Energy are outstanding?
Acorn Energy has 2.5M shares outstanding, of which 1.6M are in the public float.