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5/5MONOLITHIC POWER SYSTEMS INC (MPWR): Non-reliance / restatement

Filed 2026-02-27 · Form 8-K · Accession 0001437749-26-006112 large

Market data

Price before filing: $1,174 (2026-02-26 close, split/dividend-adjusted)
Market cap at flag: $56.11B (2026-02-27) · Latest: $59.48B (2026-10-16)

What happened next

Window	MPWR	SPY	vs SPY
30 days	-15.1%	-8.1%	-7.0%	2026-03-30
90 days	+38.7%	+9.8%	+28.9%	2026-05-28
180 days	+10.9%	+11.7%	-0.9%	2026-08-26

Return from the last close before the filing date to the first close on/after the window end. Pending windows have not fully elapsed. Past performance says nothing certain about the future.

Insider trading around this filing

90 days before the flag: 6 insiders sold $298.0M (87 sales)
30 days after: 1 insider sold $33K (1 sale)

Date	Insider	Type	Shares	Price	Value	10b5-1 plan	Source
2025-12-01	BLEGEN THEODORE EVP and CFO	Sale	40	$899.73	$36K	yes	Form 4
2025-12-01	BLEGEN THEODORE EVP and CFO	Sale	40	$900.88	$36K	yes	Form 4
2025-12-01	BLEGEN THEODORE EVP and CFO	Sale	80	$901.88	$72K	yes	Form 4
2025-12-01	BLEGEN THEODORE EVP and CFO	Sale	40	$902.31	$36K	yes	Form 4
2025-12-01	BLEGEN THEODORE EVP and CFO	Sale	120	$904.38	$109K	yes	Form 4
2025-12-01	BLEGEN THEODORE EVP and CFO	Sale	80	$906.84	$73K	yes	Form 4
2025-12-01	BLEGEN THEODORE EVP and CFO	Sale	80	$907.59	$73K	yes	Form 4
2025-12-01	BLEGEN THEODORE EVP and CFO	Sale	480	$908.69	$436K	yes	Form 4
2025-12-01	BLEGEN THEODORE EVP and CFO	Sale	1,984	$909.00	$1.8M	yes	Form 4
2025-12-01	BLEGEN THEODORE EVP and CFO	Sale	56	$911.59	$51K	yes	Form 4
2025-12-24	Lee Victor K Director	Sale	197	$949.70	$187K	yes	Form 4
2025-12-24	Lee Victor K Director	Sale	280	$950.64	$266K	yes	Form 4
2025-12-24	Lee Victor K Director	Sale	160	$951.60	$152K	yes	Form 4
2025-12-24	Lee Victor K Director	Sale	83	$952.37	$79K	yes	Form 4
2025-12-24	Lee Victor K Director	Sale	200	$953.70	$191K	yes	Form 4
2025-12-24	Lee Victor K Director	Sale	80	$955.08	$76K	yes	Form 4
2026-01-02	BLEGEN THEODORE EVP and CFO	Sale	80	$927.61	$74K	yes	Form 4
2026-01-02	BLEGEN THEODORE EVP and CFO	Sale	194	$930.86	$181K	yes	Form 4
2026-01-02	BLEGEN THEODORE EVP and CFO	Sale	80	$933.64	$75K	yes	Form 4
2026-01-02	BLEGEN THEODORE EVP and CFO	Sale	40	$934.74	$37K	yes	Form 4
2026-01-02	BLEGEN THEODORE EVP and CFO	Sale	80	$935.33	$75K	yes	Form 4
2026-01-02	BLEGEN THEODORE EVP and CFO	Sale	120	$936.50	$112K	yes	Form 4
2026-01-02	BLEGEN THEODORE EVP and CFO	Sale	460	$938.52	$432K	yes	Form 4
2026-01-02	BLEGEN THEODORE EVP and CFO	Sale	117	$939.75	$110K	yes	Form 4
2026-01-02	BLEGEN THEODORE EVP and CFO	Sale	40	$940.03	$38K	yes	Form 4
2026-02-27: red flag filed

Showing 25 of 88 transactions.

Open-market purchases and sales (Form 4 codes P and S) by officers, directors and 10% owners, by transaction date, from 2025-11-29 to 2026-03-29. Excludes option exercises, grants, gifts and tax withholding. Amended filings replace the originals; joint filings count once. Foreign private issuers do not file Form 4. Many insider sales are pre-scheduled (10b5-1 plans) and are not by themselves a sign of wrongdoing.

Verified excerpt

"(the "Company"), after discussion with senior management, determined that the Company's previously issued audited consolidated financial statements included in its annual report on Form 10-K for the fiscal year ended December 31, 2024, filed on March 3, 2025, and each of the Company's previously issued unaudited condensed consolidated financial statements included in its quarterly reports on Form 10-Q for each of..."

Quoted from the filing. Source

What this means

The company says previously issued financial statements should no longer be relied upon (8-K Item 4.02). This is one of the most serious accounting red flags: past reported numbers were wrong and will be restated.

Read the original filing on SEC.gov →