AMPX CLUSTER SEC Filing Analysis

Latest settled — T+5d

AMPX ▲ +7.20% at T+5d

SHORT call ✗ call lost -7.20% · α vs SPY -7.49% · entry $20.28 → $21.74

Next anchor: T+20d in 16d

Last close $18.83 (close Jun 8) · +7.15% from $20.28 entry (call sign-flipped)

Entry anchored
May 28, 04:51 PM ET
via Databento tick

T+1d

+7.25%

call -7.25% · α -6.97%

$21.75

settled 12d ago

T+5d

+7.20%

call -7.20% · α -7.49%

$21.74

settled 6d ago

T+20d

—

call — · α —

—

in 16d

T+60d

—

call — · α —

—

in 2mo

Price Chart

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Executive Summary

Four Amprius insiders, including the CEO and CTO, sold a total of $2.28M in shares over a 7-day window. The CEO and a director sold ~$1.9M combined at ~$14.79 on May 21, while the CTO and another director sold ~$375K at higher prices later in the week. At a $2.4B market cap, the total represents ~0.1% of market cap — a modest but notable cluster, amplified by C-suite participation and the cross-filing context of recent earnings and press activity.

Key Financial Metrics

Direction

selling

Total Value

$2.3M

Insiders

4

Actionable Insight

The CEO and CTO both sold shares in the same week, which is a bearish signal for a high-growth stock. While the dollar amount is modest relative to market cap, the involvement of top executives and the cross-filing amplifier context warrant caution. Monitor for any upcoming negative news or guidance revision that may have prompted the sales.

Key Facts

CEO Thomas Stepien sold 60.7K shares for $898K on May 21 at $14.79.
Director Sun Kang sold 67.8K shares for $1.00M on May 21 at $14.79.
CTO Stefan Ionel sold 3.2K shares for $55K on May 27 at $17.19.
Director Donald Dixon sold 17.9K shares for $320K on May 26 at $17.90.
Total insider sales of $2.28M represent ~0.1% of $2.4B market cap.
All four trades were open-market sales (code S); no 10b5-1 plan pattern is evident from the data.
Cross-filing context includes recent earnings and press activity, which the actuarial model flags as amplifiers for insider sales.

Financial Impact

Total insider sales of $2.28M, or ~0.1% of market cap.

dilutioninsider sentiment

Risk Factors

CEO and CTO selling concurrently may signal insider concern about near-term valuation or business outlook.
The stock has rallied significantly (prior reports show large positive moves), increasing the risk of a pullback.
No 10b5-1 plan identified — sales appear discretionary.

Market Snapshot

Exchange

NYSE

Sector

Miscellaneous Electrical Machinery, Equipment & Supplies

Analyst Consensus

93% bullish (15 analysts)

Documents Analyzed

This report is based on 1 SEC document filed with EDGAR.

Document	Accession Number
CLUSTER Data (Synthetic)	cluster-AMPX-1780006411015

7 reports for AMPX

T+1T+5T+20T+60

60% Hit rate 3 of 5 directional calls best @ T+60▲ +46.07%Mar 4, 2026

Filters

Reports for AMPX — sortable, filterable
	Type				Now
May 28, 2026 12d ago	Insider Cluster BEARISH ★ 5/10	$20.28 $21.74	▼ −7.20%	▼ −7.49%	$18.83 (+7.15%)
May 28, 2026 12d ago	Insider Cluster BEARISH ★ 5/10	$20.28 $19.69	▲ +2.91%	▲ +0.39%	$18.83 (+7.15%)
May 26, 2026 14d ago	Insider Cluster BEARISH ★ 5/10	$17.16 $22.91	▼ −33.51%	▼ −32.30%	$18.83 (−9.73%)
May 26, 2026 14d ago	Insider Cluster NEUTRAL ★ 2/10	$17.16 $22.91	▲ +33.51%	▲ +32.30%	$18.83 (+9.73%)
Mar 12, 2026 12w ago	Insider Cluster BEARISH ★ 7/10	$18.29 $19.11	▼ −4.48%	▼ −5.46%	$18.83 (−2.95%)
Mar 4, 2026 13w ago	8-K BULLISH ★ 8/10	$14.89 $18.29	▲ +22.83%	▲ +25.07%	$18.83 (+26.46%)
Feb 23, 2026 15w ago	Insider Cluster BEARISH ★ 6/10	$10.20 $11.59	▼ −13.63%	▼ −13.01%	$18.83 (−84.61%)

US Market Status

Market Closed — Opens in 7h 27m

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