Regulatory filings disclosed on Tuesday reveal a string of significant insider trades across multiple sectors of the U.S. market. The period saw a mix of purchases and large-scale dispositions reported on SEC forms, with transactions spanning specialty chemicals and laboratory supplies, industrials, regional banking depositary shares, real estate investment trusts, semiconductors, interconnect manufacturers, aviation leasing and healthcare services.
Top buys
Avantor, Inc. (NASDAQ: AVTR) recorded one of the larger insider purchases. Director Simon Dingemans acquired 25,000 shares of common stock on May 1, 2026, for a total of $203,500. The stock was purchased at $8.14 per share through an indirect acquisition via a spouse. The filing notes that Mr. Dingemans now indirectly holds those 25,000 shares in addition to 6,225 shares that he holds directly. At the time of the filing the stock was trading near $8.05 and has declined about 36% over the past year; a Fair Value note cited in the filings indicates InvestingPro considers the shares undervalued at current prices.
Ecolab Inc. (NYSE: ECL) also showed insider buying. Director David MacLennan purchased 800 shares of common stock on May 4, 2026, at $256.912 per share, for an aggregate value of $205,529. The transaction was a direct purchase, and the filing states Mr. MacLennan now directly owns 24,230.01 shares of Ecolab common stock. In addition to the direct holdings, the filing reports indirect ownership of 3,500 shares held through the Kathleen F. MacLennan Revocable Trust and 709 shares held through siblings’ trusts. The stock was trading close to a reported 52-week low of $249.04, while InvestingPro’s Fair Value assessment flagged the shares as potentially overvalued relative to that model.
First Busey Corp (NASDAQ: BUSE) saw a purchase reported by Chief Accounting Officer Scott A. Phillips. On May 4, 2026, Mr. Phillips bought 5,000 depositary shares at $25.9015 each, for a total consideration of $129,507. The filing clarifies that each depositary share represents a 1/40th interest in one share of the issuer’s 8.25% Fixed-Rate Non-Cumulative Perpetual Preferred Stock, Series B. At the time of the transaction the depositary shares were trading around $26.56, a level that reflects a year-to-date increase of roughly 27%, and InvestingPro’s analysis described the security as appearing undervalued.
Top sells
Regency Centers Corp. (NASDAQ: REG) reported a substantial set of indirect sales by Executive Chairman Martin E. Stein Jr. The filings show Mr. Stein Jr. disposed of 274,615 shares of common stock on May 4, 2026, for proceeds of approximately $21.5 million. The sales occurred at prices between $78.175 and $78.69 per share across three separate indirect transactions. At the time of the filing the shares were trading near $78.88 and close to a 52-week high of $81.66. InvestingPro’s valuation commentary included in the filings indicated the stock appears overvalued at current market levels.
Micron Technology (NASDAQ: MU) disclosed a CEO sale. President and Chief Executive Officer Sanjay Mehrotra sold a total of 39,995 shares of common stock on May 1, 2026, in multiple transactions reported on a Form 4. The total value of the sales was $21,450,554, with individual trade prices ranging from $511.91 to $545.39 per share. The filing specifies these sales were executed pursuant to a Rule 10b5-1 trading plan that Mr. Mehrotra adopted on January 30, 2026. Since those transactions the stock has risen substantially to a level reported at $640.20, representing a 698% gain over the past year. InvestingPro analysis included in the filing materials notes that Micron’s market price currently sits above the platform’s Fair Value estimate and lists the company among its Most Overvalued stocks.
Amphenol Corp (NASDAQ: APH) disclosed a multi-day selling program by President and CEO Richard Adam Norwitt. Between May 1 and May 5, 2026, Mr. Norwitt sold a total of 130,775 shares of Class A Common Stock for about $18.7 million in aggregate proceeds. The filings detail the sequence: on May 1, 61,072 shares were sold at a weighted average price of $143.8951 with trades spanning $143.50 to $146.30; on May 4, 52,203 shares were sold at a weighted average of $142.0416 with prices between $142.00 and $142.1351; and on May 5, 17,500 shares were sold at a weighted average price of $143.2061 with trades between $143.1550 and $143.2514. The filings note the stock has returned 71.7% over the prior year and that InvestingPro’s Fair Value assessment currently views the shares as overvalued relative to that model.
FTAIAviation Ltd. (NASDAQ: FTAI) reported a sizable disposition by a director. According to a Form 4 filed on May 5, 2026, director Martin Tuchman sold 254,260 ordinary shares over several days in early May for total proceeds of $61,534,493. The reported sale prices ranged from $238.27 to $245.66 per share. At the time the stock was trading at $244.20 and had delivered a 145% return over the previous year, including a 13% gain in the last week preceding the filing.
DaVita Inc. (NASDAQ: DVA) featured a large block sale by a major shareholder. Berkshire Hathaway Inc. and its controlling stockholder, Warren E. Buffett, reported the sale of 1,220,376 shares of common stock on May 1, 2026, at a price of $149.8429 per share, generating proceeds of approximately $182.8 million. After the transaction the filing reports Berkshire Hathaway and Mr. Buffett together retain ownership of 28,880,209 shares of DaVita common stock. The shares have since traded up to $157.04, close to a reported 52-week high of $159.42, and the filing notes the stock has appreciated roughly 30% over the past six months.
Context and considerations
The filings illustrate a mix of insider behavior: selected directors and officers increasing positions through direct or indirect purchases, alongside substantial sales by executives and major shareholders. Several entries reference InvestingPro valuation commentary, which in some cases identifies the shares as undervalued and in others flags them as overvalued versus the platform’s Fair Value calculation. The filings also disclose the mechanics of certain transactions - for example, the First Busey purchases were in the form of depositary shares each representing a fractional interest in a series of preferred stock, and Micron’s sales were executed under a Rule 10b5-1 plan established earlier in the year.
Investors often review insider activity as one input among many; the disclosures themselves do not explain the motives behind each trade. The filings record the quantities, prices, and structures of the transactions and attach valuation commentary from InvestingPro where available.
Key takeaways
- Significant insider purchases were recorded at Avantor, Ecolab and First Busey, while major sales were reported at Regency Centers, Micron, Amphenol, FTAI Aviation and DaVita.
- The filings include structured purchases and sales - depositary shares in Busey’s case and Rule 10b5-1-plan sales in Micron’s case - highlighting different transaction mechanics executives use to trade.
- InvestingPro valuation notes included with the filings offer mixed signals: some stocks are described as undervalued, others as overvalued, underscoring divergent assessments between insider actions and that particular fair-value framework.
Risks and uncertainties
- Insider trades do not, by themselves, reveal intent - sales can reflect personal financial planning or portfolio management rather than a change in company fundamentals, and purchases may be influenced by a range of non-operational factors.
- Valuation commentary cited in the filings (from InvestingPro) presents differing viewpoints relative to market prices; reliance on a single fair-value estimate introduces model risk for investors interpreting these trades.
- Concentration of activity in specific sectors - including real estate, semiconductors and healthcare - means market moves in those sectors could disproportionately affect the short-term interpretation of the disclosed transactions.
Monitoring Form 4 filings provides transparency about how insiders and large holders transact in their companies’ securities. These disclosures supply concrete transaction details - dates, share counts, price ranges and ownership changes - that market participants can weigh alongside broader fundamental and technical analysis when forming investment judgments.