The simultaneous selling by the CEO, CTO, and two directors — all within 5 days — is a coordinated cluster that warrants attention. While the dollar amount is modest relative to market cap, the breadth of C-suite and board participation is unusual. Monitor for any upcoming 8-K (earnings pre-announcement, material agreement, or offering) that may have triggered these sales. The cross-filing amplifiers suggest this cluster is more informative when combined with earnings, offering, or press contexts — watch for those filings in the next 30 days.
Price Chart
Executive Summary
Four Amprius insiders, including the CEO and CTO, sold a total of $2.65M in open-market sales over a 7-day window. The CEO alone sold $898K, and the CTO sold $426K. At $2.4B market cap, the cluster represents ~0.11% of market cap — modest in size but notable for the breadth of C-suite and director participation.
Key Financial Metrics
Key Facts
- CEO Thomas Stepien sold 60,700 shares for $898K on 2026-05-21
- CTO Stefan Constantin Ionel sold 28,800 shares for $426K on 2026-05-21
- Director Sun Kang sold 67,800 shares for $1.00M on 2026-05-21
- Director Donald Dixon sold 17,895 shares for $320K on 2026-05-26
- Total cluster value: $2.65M, representing ~0.11% of $2.4B market cap
- All sales were open-market (code S), not tax-withholding or derivative exercises
Financial Impact
$2.65M in insider sales over 7 days, ~0.11% of market cap
Risk Factors
- Potential undisclosed negative catalyst (earnings miss, offering, or operational setback) prompting coordinated insider selling
- CEO and CTO both selling at same price ($14.79) suggests a shared liquidity event or blackout-window opening rather than independent bearish views
Market Snapshot
Investment Themes
Documents Analyzed
This report is based on 1 SEC document filed with EDGAR.
| Document | Accession Number |
|---|---|
| CLUSTER Data (Synthetic) | cluster-AMPX-1780006231209 |
Filters
| Type | Now | ||||
|---|---|---|---|---|---|
Oct 9, 2026 17d ago | S-3ASR | $8.87 | awaiting T+60 | — | $8.82 (−0.56%) |
Sep 25, 2026 4w ago | 8-K | $9.60 | awaiting T+60 | — | $8.82 (−8.13%) |
Aug 25, 2026 8w ago | Insider Cluster | $10.20 | awaiting T+60 | — | $8.82 (−13.53%) |
Aug 13, 2026 10w ago | 8-K | $12.51 | awaiting T+60 | — | $8.82 (−29.50%) |
Aug 1, 2026 12w ago | Institutional Cluster | $10.12 | awaiting T+60 | — | $8.82 (+12.85%) |
Jun 11, 2026 19w ago | Insider Cluster | $16.31 $10.39 | ▼ −36.30% | ▼ −39.56% | $8.82 (−45.92%) |
Jun 11, 2026 19w ago | Institutional Cluster | $17.10 $9.89 | ▼ −42.16% | ▼ −46.56% | $8.82 (−48.42%) |
Jun 8, 2026 20w ago | 144 | $4.84 | awaiting T+60 | — | $8.82 (−82.23%) |
May 28, 2026 21w ago | 144 | — | awaiting T+60 | — | — |
May 28, 2026 21w ago | Insider Cluster | $20.28 $9.86 | ▲ +51.38% | ▲ +52.56% | $8.82 (+56.51%) |
US Market Status
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