MPWR's record $59M CEO sale leads AI chip insider exodus, Murchinson demands NNDM board overhaul

Today's window (May 21 13:39 ET → May 22 13:00 ET) logged 14 Form 4 insider trades and 19 institutional filings (13D/G). The dominant signal: AI and semiconductor insiders sold into strength across three names on the same day, while an activist fund formally escalated its campaign against a 3D-printing company. Temasek's first-ever Luckin Coffee disclosure rounds out a session heavy on disclosure-driven catalysts.

Three AI-adjacent companies — Monolithic Power Systems (MPWR), Astera Labs (ALAB), and CoreWeave (CRWV) — all saw large insider sales filed for May 18, the same trading day. Each stock had run hard in the prior year; each executive sold at or near 52-week highs.

MPWR CEO (name not disclosed in source filings) sold 40,000 shares at $1,482.75 per share through the company's employee stock purchase plan, generating $59.3M 1. This is the largest of his 161 recorded sales, representing a 3.87% reduction in his position. MPWR, a semiconductor company that makes power management chips widely used in data center and AI infrastructure builds, had risen 123.53% in the prior year before the sale. Thirty days into this run, seven insiders across the company filed nine separate sell transactions — the CEO's record sale is the capstone of that cluster.

ALAB (Astera Labs, a fabless semiconductor company focused on high-speed connectivity for AI data centers) saw its CEO Jitendra Mohan execute two separate transactions on May 18-19: a planned 10b5-1 sale of 142,071 shares generating approximately $31.3M, followed by a sell-to-cover of 93,444 shares worth roughly $21.5M 2. President and COO Sanjay Gajendra simultaneously sell-to-covered 93,398 shares for approximately $21.5M 2. A third insider, Philip Mazzara, also sold during the week, bringing the combined ALAB insider total to approximately $147.3M for the week 3. ALAB was trading near its 52-week high of $287.70, having returned 204–212% over the prior year. The sell-to-cover portions are non-discretionary (triggered automatically by tax-withholding mechanics on vesting awards), but the CEO's 10b5-1 sale is a pre-planned discretionary transaction.

CRWV CSO Brian Venturo sold 375,000 Class A shares on May 18 under a 10b5-1 plan adopted in November 2025, totaling approximately $38.0M at a weighted average price of $99.37–$103.85 2. The shares were sold indirectly through West Clay Capital LLC and a family trust. CoreWeave is a GPU cloud infrastructure company that went public in early 2025.

The same-day pattern across all three names is consistent with coordinated profit-taking after a multi-month AI infrastructure rally rather than any single company-specific concern. All three sales were either 10b5-1 plans (pre-scheduled) or automated tax covers — none shows evidence of discretionary urgency. That said, the sheer volume ($150M+ across one trading day in this subsector) is a data point worth tracking if AI chip stocks face near-term multiple compression.

Murchinson, a multi-strategy fund led by CEO Marc Bistricer, filed its 16th amendment to its Schedule 13D on Nano Dimension (NNDM) on May 21, formally demanding that the company call a special shareholder meeting 4. Nano Dimension is an Israeli-headquartered additive manufacturing (3D printing) company for electronic components.

Murchinson holds 15.55 million ADS (American Depositary Shares), representing 7.4% of outstanding shares based on 209.2 million shares as of May 5, 2026 4. The stake is split across three entities: Nomis Bay (4.67M shares, cost ~$13.7M), BPY (3.11M shares, cost ~$9.1M), and managed positions (7.78M shares, cost ~$22.8M).

The formal demand — sent to NNDM's board on May 21 after Murchinson began soliciting shareholder support via written consent cards on May 19 — contains four concrete proposals:

This is Amendment #16, which signals the campaign has been building for an extended period. The intensity of the ask — four structural governance changes simultaneously — goes beyond typical activist pressure for a seat or a specific policy change. Murchinson appears to be pushing for full control over the board's composition and decision-making framework. NNDM shareholders will need to assess whether management responds with a settlement or contests the special meeting request.

Fortune Brands Innovations (FBIN), a home and security products company (brands include Master Lock, Fiberon, and Moen), has been one of the harder-hit consumer discretionary names in 2026, down approximately 30% year-to-date as of mid-May.

Director Edward Garden — who controls FBIN shares through entities GI SPV II L.P. and Green 73 LLC — bought 408,900 shares on May 19–20, paying a weighted average of roughly $33.40 and $33.28 respectively, for a total outlay of approximately $13.66M 1 2. This is the 21st of Garden's 40 all-time purchases in FBIN, and the buy came at a price touching the 52-week intraday low of $32.34. His position increased by 12.95%.

This is a meaningful signal for three reasons: the buy is discretionary (not a compensation plan), the size ($13.7M) is substantial relative to the stock's market cap, and it is part of a long pattern of the same director buying on dips rather than selling into strength.

RDW footnote: AE Red Holdings, a director at Redwire Corp (RDW), sold 15.25M shares at $13.75 each ($209.6M) on May 18 — a 99.16% liquidation of their position 1. This is the fourth sale in 30 days by this entity, following a consistent monthly exit pattern. The timing — selling into a 21.4% weekly rally — looks like a deliberate rip-sale strategy. Prior issues covered the initial exit; this filing confirms near-complete liquidation.

Singapore's sovereign wealth fund Temasek Holdings filed a 13G on Luckin Coffee (LKNCY) dated May 22, disclosing beneficial ownership of 137.0 million Class A shares representing a 6.4% stake 5. Temasek Capital (China), a wholly owned subsidiary, holds 111.7M of those shares (5.2%). The stake includes 32.3M shares held directly and 104.7M shares in the form of ADS (1 ADS = 8 Class A shares).

This is the first time Temasek has disclosed a position above the 5% SEC reporting threshold in Luckin Coffee, making it the most internationally visible endorsement yet of Luckin's post-fraud recovery story. Luckin filed for bankruptcy protection in 2020 after a $300M accounting fraud but emerged in 2022 and has since rebuilt itself into one of China's largest coffee chains by store count. The filing is a passive 13G (investment only, no control intent), but sovereign funds rarely disclose stakes at this size without a multi-year conviction behind the position.

Peter Kellogg, a private investor, filed a 13D/A on Mercer International (MERC) showing he has acquired 1 million additional shares at $0.84–$0.96 per share between May 12–19, lifting his total stake to 25.38M shares, or 37.9% of the company 6. Mercer International is a Vancouver-based pulp and paper manufacturer. Kellogg's accumulation at sub-$1 prices — in a 13D (not the passive 13G) — signals engagement rather than passive index-following. This is Amendment #11, suggesting steady, long-term accumulation of a beaten-down industrial name.

Prospect Capital CEO John Barry III bought 200,000 shares of PSEC in the open market on May 21 at weighted averages of $2.2766 and $2.2413, using personal funds 7. Barry now holds 130.6M shares outright (26.1% of shares outstanding based on 501M shares as of May 6). Prospect Capital is a Business Development Company (BDC) — a closed-end fund structure that lends to middle-market companies. Insider buying by a BDC's own CEO at sub-$2.30 per share, given that BDCs trade at discounts or premiums to net asset value, typically signals that the CEO believes current NAV discount makes the stock cheap relative to book.

HUBC watch: Two separate individuals filed independent 13G disclosures on Hub Cyber Security on the same day, pushing combined disclosed ownership above 36%. Hub Cyber Security (HUBC) is an Israeli cybersecurity company. Whether White and Tu are acting in concert — which would require a joint 13D rather than separate 13Gs — is a question regulators or the company could pursue. Neither filing references a relationship between the two filers.

MP Materials note: COO Rosenthal's $962K buy is the largest single purchase in his seven-transaction history at MP, a California-based rare earth mining and processing company. InvestingPro flags MP as trading above estimated fair value, making this COO buy a noteworthy contrarian data point worth watching if the stock corrects.