SIMO SEC Filing News — Silicon Motion Technology Corporation

Latest SEC filings for Silicon Motion Technology Corporation (SIMO) explained in plain English. Covers insider buying and selling (Form 4), proposed insider sales (Form 144), material company events (8-K), and quarterly & annual reports (10-Q / 10-K). StrongBuyAnalytics provides navigation and brief excerpts or summaries; original filings remain at the SEC/source links and were authored by their filers, not StrongBuyAnalytics. Filing dates shown are source dates. Coverage and detection can be delayed or incomplete because of SEC availability, amendments, parsing, caching, or outages. Latest source filing date shown: 2026-06-24.

Silicon Motion Technology Corporation, together with its subsidiaries, designs, develops, and markets NAND flash controllers for solid-state storage devices and related devices in China, Japan, Singapore, Taiwan, Korea, the United States, and internationally. It offers controllers for computing-grade solid state drives (SSDs), which are used in PCs and other client devices; enterprise-grade SSDs used in enterprise and hyperscale data centers; eMMC and UFS mobile embedded storage for use in smart…
Sector: Technology Industry: Semiconductors Market Cap: $7.3B
20
Total Filings
0
Bullish Classifications
3
Bearish Classifications
3
Insider Transactions
0
Material Events (8-K)
0
Periodic Reports
Rule-based classifications for SIMO currently lean bearish. Of the 20 filing records displayed, 3 carry bearish classifications (such as insider sales or negative 8-K disclosures) versus 0 bullish. This does not necessarily signal fundamental deterioration — insiders sell for many reasons — but it is worth monitoring alongside the company's core financial metrics.
SIMO Filing Activity Snapshot 2024-06-07 — 2026-06-24
Insider Transactions (Form 4)
0 buys vs 3 sells
Net insider selling in this period — insiders sell for many reasons beyond conviction.
Largest Form 144 Filing
$3.22M
LIN KUAN-MING · 2026-06-04
10,500 shares · Form 144
Form 144 Notices
17
Proposed insider sales filed — Form 144 is a notice of intent, not a confirmed transaction. Actual sales are confirmed via Form 4.
Insider Transactions 3 · Forms 3, 4 and 5

A Form 4 is filed within two business days of a company insider — an officer, a director, or a holder of more than ten percent of the stock — changing their position in the shares. All 3 filings in this group are Form 4s for Silicon Motion Technology Corporation.

The difficulty with reading these filings as a group is that a single form type covers transactions that mean entirely different things. An executive spending their own money to buy stock and an executive having shares withheld to pay tax on a vesting grant both appear as a Form 4. Every filing below is therefore tagged with the nature of the underlying transaction, taken from the transaction code reported on the form itself.

Across the 3 insider filings shown, the breakdown is 3 open-market sale. 3 of them involved a discretionary open-market trade; the rest are compensation and administrative mechanics.

What each transaction type means

Open-market sale ×3
The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.
Form 4 Open-market sale Insider Selling 2026-06-24

SIMO insider SHIEH HAN-PING (Director) sold 2,000 shares (~$629.2K)

SHIEH HAN-PING, listed as Director at Silicon Motion Technology CORP, reported an open-market sale of 2,000 SIMO shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code Nature Shares Price Value
S Open-market sale 1,000 $301.25 $301.2K
S Open-market sale 1,000 $328.00 $328.0K
Filing: Form 4 (Insider Transaction) Insider: SHIEH HAN-PING (Director) Shares: 2,000 Est. Value: $629.2K
View on SEC EDGAR → Open Filing Document →
Form 4 Open-market sale Insider Selling 2026-06-24

SIMO insider LIN KUAN-MING (Director) sold 3,000 shares (~$930.3K)

LIN KUAN-MING, listed as Director at Silicon Motion Technology CORP, reported an open-market sale of 3,000 SIMO shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code Nature Shares Price Value
S Open-market sale 1,000 $300.00 $300.0K
S Open-market sale 1,000 $310.01 $310.0K
S Open-market sale 1,000 $320.31 $320.3K
Filing: Form 4 (Insider Transaction) Insider: LIN KUAN-MING (Director) Shares: 3,000 Est. Value: $930.3K
View on SEC EDGAR → Open Filing Document →
Form 4 Open-market sale Insider Selling 2026-05-07

SIMO insider DUANN SHII TYNG (Director) sold 1,500 shares (~$367.5K)

DUANN SHII TYNG, listed as Director at Silicon Motion Technology CORP, reported an open-market sale of 1,500 SIMO shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code Nature Shares Price Value
S Open-market sale 1,500 $245.00 $367.5K
Filing: Form 4 (Insider Transaction) Insider: DUANN SHII TYNG (Director) Shares: 1,500 Est. Value: $367.5K
View on SEC EDGAR → Open Filing Document →
Proposed Insider Sales 17 · Form 144

A Form 144 is a notice of intent to sell restricted or control securities. It is not a record that anything was sold. Silicon Motion Technology Corporation has 17 such notices in this period.

The distinction matters because a Form 144 is frequently reported as though it were a completed insider sale. The filer may sell all of the shares covered, some of them, or none at all, and there is no obligation to update the notice either way. A sale that is actually executed by an officer or director shows up separately on a Form 4, which is the filing to check before treating a proposed sale as a real one.

Form 144 Proposed Insider Sale 2026-06-04

SIMO Form 144 filed for proposed insider sale by LIN KUAN-MING (10,500 shares) ~$3.22M

LIN KUAN-MING filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: LIN KUAN-MING Shares: 10,500 Est. Value: $3.22M
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2026-05-27

SIMO Form 144 filed for proposed insider sale by Fan Robert C (500 shares) ~$136.2K

Fan Robert C filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Fan Robert C Shares: 500 Est. Value: $136.2K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2026-05-27

SIMO Form 144 filed for proposed insider sale by SHIEH HAN-PING (2,000 shares) ~$552.3K

SHIEH HAN-PING filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: SHIEH HAN-PING Shares: 2,000 Est. Value: $552.3K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2026-05-18

SIMO Form 144 filed for proposed insider sale by Fan Robert C (1,100 shares) ~$225.7K

Fan Robert C filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Fan Robert C Shares: 1,100 Est. Value: $225.7K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2026-05-01

SIMO Form 144 filed for proposed insider sale by DUANN SHII TYNG (1,500 shares) ~$328.5K

DUANN SHII TYNG filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: DUANN SHII TYNG Shares: 1,500 Est. Value: $328.5K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2026-02-24

SIMO Form 144 filed for proposed insider sale by Fan Robert (2,000 shares) ~$270.8K

Fan Robert filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Fan Robert Shares: 2,000 Est. Value: $270.8K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2025-12-09

SIMO Form 144 filed for proposed insider sale by Fan Robert (3,000 shares) ~$271.4K

Fan Robert filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Fan Robert Shares: 3,000 Est. Value: $271.4K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2025-11-10

SIMO Form 144 filed for proposed insider sale by DUANN SHII TYNG (1,000 shares) ~$95.0K

DUANN SHII TYNG filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: DUANN SHII TYNG Shares: 1,000 Est. Value: $95.0K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2025-09-16

SIMO Form 144 filed for proposed insider sale by LIN KUAN-MING (12,500 shares) ~$1.12M

LIN KUAN-MING filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: LIN KUAN-MING Shares: 12,500 Est. Value: $1.12M
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2025-09-09

SIMO Form 144 filed for proposed insider sale by SHIEH HAN-PING (6,000 shares) ~$509.1K

SHIEH HAN-PING filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: SHIEH HAN-PING Shares: 6,000 Est. Value: $509.1K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2025-08-12

SIMO Form 144 filed for proposed insider sale by SHIEH HAN-PING (6,000 shares) ~$458.3K

SHIEH HAN-PING filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: SHIEH HAN-PING Shares: 6,000 Est. Value: $458.3K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2025-06-25

SIMO Form 144 filed for proposed insider sale by SHIEH HAN-PING (2,000 shares) ~$144.0K

SHIEH HAN-PING filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: SHIEH HAN-PING Shares: 2,000 Est. Value: $144.0K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2025-05-12

SIMO Form 144 filed for proposed insider sale by DUANN SHII TYNG (4,000 shares) ~$214.2K

DUANN SHII TYNG filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: DUANN SHII TYNG Shares: 4,000 Est. Value: $214.2K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2024-12-18

SIMO Form 144 filed for proposed insider sale by Fan Robert (1,000 shares) ~$60.3K

Fan Robert filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Fan Robert Shares: 1,000 Est. Value: $60.3K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2024-12-03

SIMO Form 144 filed for proposed insider sale by DUANN SHII TYNG (3,000 shares) ~$162.0K

DUANN SHII TYNG filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: DUANN SHII TYNG Shares: 3,000 Est. Value: $162.0K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2024-06-21

SIMO Form 144 filed for proposed insider sale by YU-CHEN CHIEN (5,000 shares) ~$410.3K

YU-CHEN CHIEN filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: YU-CHEN CHIEN Shares: 5,000 Est. Value: $410.3K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2024-06-07

SIMO Form 144 filed for proposed insider sale by Fan Robert (1,000 shares) ~$80.6K

Fan Robert filed a Form 144 with the SEC indicating intent to sell SIMO (Silicon Motion Technology CORP) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Fan Robert Shares: 1,000 Est. Value: $80.6K
View on SEC EDGAR → Open Filing Document →

How we classify Silicon Motion Technology Corporation's filings

Straight from EDGAR

Each displayed record links to an original source document. StrongBuyAnalytics provides navigation and brief excerpts or summaries, not the filing itself. Parsing may omit context or contain errors, so read the original document in full.

Transaction codes, not guesswork

The nature shown on each insider filing comes from the transaction code the filer entered on the form itself — P for an open-market purchase, A for a compensation award, F for shares withheld to pay tax, M for an option exercise. Where one filing contains several codes, the transaction table lists them line by line.

Why the distinction matters

Insider activity is routinely summarised as buying or selling, which flattens together decisions that mean very different things. Shares withheld for tax on a vesting grant are an automatic administrative step; shares bought on the open market are someone committing their own money at the current price.

What this page does not tell you

A filing records what happened, not why. Form 4 does not always disclose whether a sale was executed under a pre-arranged Rule 10b5-1 plan, and no single filing is a basis for a decision on SIMO. Read these alongside the fundamentals rather than in isolation.

Frequently Asked Questions — SIMO SEC Filings

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Publisher, sources & limitations — September 15, 2026. StrongBuyAnalytics provides navigation and brief excerpts or summaries for educational use. Original filings remain at SEC EDGAR or other displayed source links; StrongBuyAnalytics does not author them. Filing dates are source dates, not publication dates for this page. Coverage can be delayed, incomplete, amended, or unavailable because of SEC/source availability, parsing, caching, or outages. Verify every material statement in the original filing.
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