Power Solutions International, Inc.
Power Solutions International, Inc. (PSIX) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · PSIX · as of Mar 31, 2025
Ownership Breakdown
66
Institutional Holders
▲ 34 vs Q4
$79.44M
Total Inst. Value
▲ $10.61M vs Q4
23.05M
Shares Outstanding
freeFloat 36.91%
3.14M
13F Shares Held
▲ 826,355 vs Q4
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
PSIX largest shareholders · institutional ownership
Q1 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
GAGNON SECURITIES LLC engines & turbines | 525.3K | 2.28% | 2.28% | $13.28B | May 9, 2025 | ▼ 324.9K |
GAGNON ADVISORS, LLC engines & turbines | 323.5K | 1.41% | 1.41% | $8.18B | May 12, 2025 | ▼ 146.7K |
PORTOLAN CAPITAL MANAGEMENT, LLC engines & turbines | 296.4K | 1.29% | 1.29% | $7.49B | May 15, 2025 | ▼ 44.8K |
VANGUARD GROUP INC engines & turbines | 274.7K | 1.19% | 1.19% | $6.94B | May 9, 2025 | NEW |
MARSHALL WACE, LLP engines & turbines | 263.1K | 1.14% | 1.14% | $6.65B | May 15, 2025 | ▲ 191.5K |
S SQUARED TECHNOLOGY, LLC engines & turbines | 163.0K | 70.87% | 70.87% | $4.12B | May 16, 2025 | ▼ 130.0K |
SUSQUEHANNA INTERNATIONAL GROUP, LLP engines & turbines | 107.4K | 46.70% | 46.70% | $2.72B | May 14, 2025 | NEW |
CITADEL ADVISORS LLC engines & turbines | 105.8K | 45.98% | 45.98% | $2.67B | May 15, 2025 | ▲ 93.5K |
BLACKROCK, INC. engines & turbines | 96.9K | 42.14% | 42.14% | $2.45B | May 2, 2025 | ▲ 95.4K |
O'SHAUGHNESSY ASSET MANAGEMENT, LLC engines & turbines | 80.6K | 35.02% | 35.02% | $2.04B | May 13, 2025 | ▲ 7.7K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q1 2025 vs prior quarter
Q1 2025
14
Increased
+494.8K shares29
New Positions
first time holders6
Decreased
−658.2K shares0
Sold Out
fully exitedNet shares change (top 50)
163.4K
+494.8K / −658.2K
Net new holders
+37
29 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
PSIX 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.
4
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 |
|---|---|---|---|---|---|---|---|
Li Xun CFO | Mar 6, 2026 | Award | 1,665 | — | — | 1.7K | Form 4 ↗ |
Du Zhaoying GC and Corp Secy | Mar 6, 2026 | Award | 1,492 | — | — | 1.5K | Form 4 ↗ |
Li Xun CFO | Feb 12, 2026 | Tax Withhold | 3,429 | $92.72 | $317.9K | 4.6K | Form 4 ↗ |
He Hong director | Dec 11, 2025 | Award | 5,000 | — | — | 23.8K | Form 4 ↗ |
SIMPKINS FRANK P director | Dec 11, 2025 | Award | 5,000 | — | — | 30.0K | Form 4 ↗ |
Du Zhaoying GC and Corp Secy | Dec 11, 2025 | Award | 700 | $65.76 | $46.0K | 700 | Form 4 ↗ |
Shea Courtney C. director | Dec 11, 2025 | Award | 5,000 | — | — | 5.0K | Form 4 ↗ |
Weichai America Corp. 10 percent owner | Sep 11, 2025 | Sale | 6,738 | $91.72 | $618.0K | 10.67M | Form 4 ↗ |
Weichai America Corp. 10 percent owner | Sep 11, 2025 | Sale | 19,351 | $92.46 | $1.79M | 10.65M | Form 4 ↗ |
Weichai America Corp. 10 percent owner | Sep 11, 2025 | Sale | 23,231 | $93.64 | $2.18M | 10.63M | 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
Power Solutions International, Inc. (PSIX) is primarily owned by institutional investors, who hold approximately 13.6% of total shares outstanding. Company insiders own approximately 63.09%, while retail and public investors account for the remaining 23.29%.
The largest institutional shareholder of Power Solutions International, Inc. is GAGNON SECURITIES LLC, holding approximately 525,291 shares — equal to 2.28% of outstanding shares — as of March 31, 2025.
A total of 66 institutional investors currently hold PSIX stock, with a combined institutional value of approximately $79,438,426 as of the most recent 13F filing period.
Frequently asked questions
PSIX ownershipPower Solutions International, Inc. (PSIX) is primarily owned by institutional investors, who hold approximately 13.6% of shares. The largest shareholder is GAGNON SECURITIES LLC with a 2.28% stake. Company insiders hold 63.09%. Data sourced from SEC Form 13F as of March 31, 2025.