AMPX CLUSTER SEC Filing Analysis

Latest settled — T+5d ⚠ clustered

AMPX ▼ -2.91% at T+5d

SHORT call ✓ call won +2.91% · α vs SPY +0.39% · entry $20.28 → $19.69

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, 2026
via day open

T+1d

+7.25%

call -7.25% · α -6.99%

$21.75

settled 12d ago

T+5d

-2.91%

call +2.91% · α +0.39%

$19.69

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 $2.65M 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

Direction

selling

Total Value

$2.6M

Insiders

4

Actionable Insight

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.

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

insider ownershipfloat

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
Historical calibration shows cluster sells at this score have a 29% probability of positive T+20 alpha — the signal is weak on average

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-1780006231209

7 reports for AMPX

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

40% Hit rate 2 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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