ESS Tech, Inc.
ESS Tech, Inc. (GWH) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · GWH · as of Sep 30, 2025
Ownership Breakdown
44
Institutional Holders
▼ 2 vs Q2
$5.69M
Total Inst. Value
▲ $1.68M vs Q2
12.60M
Shares Outstanding
freeFloat 41.03%
3.75M
13F Shares Held
▲ 724,964 vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
GWH largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
SOFTBANK GROUP CORP. miscellaneous electrical machinery, equipment & supplies | 2.40M | 19.53% | 19.53% | $3.64B | Nov 14, 2025 | — held |
AROSA CAPITAL MANAGEMENT LP miscellaneous electrical machinery, equipment & supplies | 675.4K | 5.50% | 5.50% | $1.03B | Nov 14, 2025 | NEW |
VANGUARD GROUP INC miscellaneous electrical machinery, equipment & supplies | 264.3K | 2.15% | 2.15% | $401.78M | Nov 7, 2025 | ▲ 34.5K |
GEODE CAPITAL MANAGEMENT, LLC miscellaneous electrical machinery, equipment & supplies | 56.8K | 46.30% | 46.30% | $86.37M | Nov 12, 2025 | ▲ 2.7K |
BLACKROCK, INC. miscellaneous electrical machinery, equipment & supplies | 53.1K | 43.31% | 43.31% | $80.79M | Nov 12, 2025 | ▲ 4 |
FMR LLC miscellaneous electrical machinery, equipment & supplies | 52.5K | 42.77% | 42.77% | $79.78M | Nov 13, 2025 | — held |
JANE STREET GROUP, LLC miscellaneous electrical machinery, equipment & supplies | 49.0K | 39.90% | 39.90% | $74.42M | Nov 14, 2025 | NEW |
YORKVILLE ADVISORS GLOBAL, LP miscellaneous electrical machinery, equipment & supplies | 48.4K | 39.42% | 39.42% | $73.53M | Nov 18, 2025 | NEW |
RENAISSANCE TECHNOLOGIES LLC miscellaneous electrical machinery, equipment & supplies | 27.6K | 22.46% | 22.46% | $41.89M | Nov 13, 2025 | — held |
XTX TOPCO LTD miscellaneous electrical machinery, equipment & supplies | 20.9K | 17.00% | 17.00% | $31.71M | Nov 14, 2025 | ▲ 6.1K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
13
Increased
+56.6K shares7
New Positions
first time holders4
Decreased
−2.4K shares6
Sold Out
fully exitedNet shares change (top 50)
+54.1K
+56.6K / −2.4K
Net new holders
+10
7 new / 6 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
GWH insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
1
Buy transactions
0
Sell transactions
0.00
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
WELLMAN ALEXI director | May 29, 2026 | Award | 13,513 | — | — | 52.4K | Form 4 ↗ |
Quarls Harry director | May 29, 2026 | Award | 13,513 | — | — | 68.8K | Form 4 ↗ |
Nijhawan Sandeep director | May 29, 2026 | Award | 13,513 | — | — | 42.6K | Form 4 ↗ |
Hossfeld Rich director | May 29, 2026 | Award | 13,513 | — | — | 41.4K | Form 4 ↗ |
Garabedian Raffi director | May 29, 2026 | Award | 13,513 | — | — | 53.2K | Form 4 ↗ |
Suhadolnik Kate Eileen Chief Financial Officer | May 21, 2026 | Sale | 1,735 | $0.92 | $1.6K | 162.7K | Form 4 ↗ |
Suhadolnik Kate Eileen Chief Financial Officer | May 22, 2026 | Sale | 1,922 | $0.93 | $1.8K | 160.8K | Form 4 ↗ |
Goodman Kelly F. SEE REMARKS | May 21, 2026 | Sale | 2,482 | $0.92 | $2.3K | 213.4K | Form 4 ↗ |
Goodman Kelly F. SEE REMARKS | May 22, 2026 | Sale | 2,751 | $0.93 | $2.6K | 210.6K | Form 4 ↗ |
Suhadolnik Kate Eileen Chief Financial Officer | Feb 20, 2026 | Sale | 741 | $1.54 | $1.1K | 164.4K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
ESS Tech, Inc. (GWH) is primarily owned by institutional investors, who hold approximately 29.7% of total shares outstanding. Company insiders own approximately 58.97%, while retail and public investors account for the remaining 11.30%.
The largest institutional shareholder of ESS Tech, Inc. is SOFTBANK GROUP CORP., holding approximately 2.40 million shares — equal to 19.53% of outstanding shares — as of September 30, 2025.
A total of 44 institutional investors currently hold GWH stock, with a combined institutional value of approximately $5,692,877 as of the most recent 13F filing period.
Frequently asked questions
GWH ownershipESS Tech, Inc. (GWH) is primarily owned by institutional investors, who hold approximately 29.7% of shares. The largest shareholder is SOFTBANK GROUP CORP. with a 19.53% stake. Company insiders hold 58.97%. Data sourced from SEC Form 13F as of September 30, 2025.