STOCK TITAN
  1. Home
  2. Sec-filings
  3. ALAB
  4. [Form 4] Astera Labs, Inc. Insider Trading Activity

Astera Labs counsel auto-sells 14,076 RSU shares

Astera Labs, Inc. General Counsel and Secretary Philip Mazzara reported automatic sales of company stock tied to tax withholding.

Filing Impact
(Very High)
Filing Sentiment
(Negative)
Form Type
4

Rhea-AI Filing Summary

Astera Labs, Inc. General Counsel and Secretary Philip Mazzara reported automatic sales of company stock tied to tax withholding. On May 18, 2026, he sold a total of 14,076 shares of Astera Labs common stock in open-market transactions.

According to the footnotes, these shares were required to be sold to satisfy tax withholding obligations from the vesting and settlement of previously granted restricted stock units. The company had elected in advance to use a “sell to cover” method, so the trades were automatic rather than discretionary. The shares were sold at weighted-average prices within ranges that span from about $216.10 to $235.94 per share.

Positive

  • None.

Negative

  • None.
Insider Mazzara Philip
Role General Counsel and Secretary
Sold 14,076 shs ($3.26M)
Type Security Shares Price Value
Sale Common Stock 9,204 $235.36 $2.17M
Sale Common Stock 990 $235.4146 $233K
Sale Common Stock 116 $233.1866 $27K
Sale Common Stock 99 $232.808 $23K
Sale Common Stock 387 $231.3126 $90K
Sale Common Stock 186 $230.2814 $43K
Sale Common Stock 55 $229.5364 $13K
Sale Common Stock 275 $226.713 $62K
Sale Common Stock 90 $225.7602 $20K
Sale Common Stock 35 $225.0051 $8K
Sale Common Stock 245 $223.7453 $55K
Sale Common Stock 189 $222.2011 $42K
Sale Common Stock 170 $221.0062 $38K
Sale Common Stock 274 $220.20 $60K
Sale Common Stock 356 $218.8679 $78K
Sale Common Stock 364 $218.0567 $79K
Sale Common Stock 646 $216.972 $140K
Sale Common Stock 395 $216.3056 $85K
Holdings After Transaction: Common Stock — 104,139 shares (Direct)
Footnotes (18)
  1. F1. Represents shares of the Issuer's Common Stock required to be sold by the Reporting Person to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units previously granted to the Reporting Person. Such sales were automatic and mandated by an election of the Issuer made in advance of the vesting event to require the satisfaction of tax withholding obligations to be funded by a "sell to cover", and does not represent a discretionary trade by the Reporting Person.
  2. F2. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $235.9400 to $235.3600, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  3. F3. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $233.9800 to $233.1600, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  4. F4. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $232.9700 to $232.7700, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  5. F5. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $231.9000 to $230.9300, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  6. F6. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $230.79000 to $229.9400, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  7. F7. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $229.7900 to $228.9350, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  8. F8. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $227.2000 to $226.2800, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  9. F9. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $226.1800 to $225.2700, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  10. F10. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $225.0500 to $224.5000, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  11. F11. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $223.9900 to $223.3000, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  12. F12. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $222.6400 to $221.6800, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  13. F13. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $221.6400 to $220.6500, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  14. F14. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $220.5200 to $219.7000, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  15. F15. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $219.5100 to $218.5300, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  16. F16. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $218.5000 to $217.5400, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  17. F17. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $217.5000 to $216.5200, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
  18. F18. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $216.4900 to $216.1000, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
Shares sold 14,076 shares Total common stock sold on May 18, 2026
Sale price range $216.10–$235.94 per share Weighted-average transaction price ranges from Form 4 footnotes
Largest single sale block 9,204 shares One open-market transaction at $235.3600 per share
Transaction count 18 transactions Non-derivative open-market sale entries reported
sell to cover financial
"to require the satisfaction of tax withholding obligations to be funded by a "sell to cover""
Sell to cover is when a person who receives company stock through options or awards sells just enough shares immediately to pay required taxes, exercise costs, or fees, keeping the rest. Think of it like cashing part of a bonus to cover the tax bill so you can keep the remainder. For investors, it can create predictable small selling pressure and slightly change the number of shares actually held by insiders without increasing long‑term dilution.
restricted stock units financial
"vesting and settlement of restricted stock units previously granted to the Reporting Person"
Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.
weighted average price financial
"The price reported in Column 4 is a weighted average price."
Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transaction did Astera Labs (ALAB) report for Philip Mazzara?
Astera Labs reported that General Counsel and Secretary Philip Mazzara sold 14,076 shares of common stock. The transactions occurred on May 18, 2026 and were linked to tax withholding from the vesting of previously granted restricted stock units under a sell-to-cover arrangement.

Why did Philip Mazzara’s Astera Labs (ALAB) shares get sold?
The shares were sold to cover tax withholding obligations from vesting restricted stock units previously granted to Philip Mazzara. The issuer had elected in advance to fund these withholding obligations through automatic “sell to cover” transactions, so the trades were not discretionary open-market sales by him.

How many Astera Labs (ALAB) shares did Philip Mazzara sell in this Form 4?
Philip Mazzara sold a total of 14,076 shares of Astera Labs common stock. These shares were sold in multiple open-market transactions on May 18, 2026 specifically to satisfy tax withholding tied to restricted stock unit vesting, according to the Form 4 footnotes.

At what prices were Philip Mazzara’s Astera Labs (ALAB) shares sold?
The reported sale prices were weighted averages from numerous trades over a price range. Footnotes state the transactions occurred at weighted-average prices within ranges spanning from approximately $216.10 per share up to $235.94 per share during the May 18, 2026 trading session.

Were Philip Mazzara’s Astera Labs (ALAB) stock sales discretionary trades?
No. The Form 4 footnotes explain that the sales were automatic and mandated by an advance issuer election. The company required tax withholding obligations on vested restricted stock units to be satisfied via “sell to cover” transactions, so these were not discretionary market-timing decisions by Mazzara.

What does “sell to cover” mean in the Astera Labs (ALAB) Form 4?
“Sell to cover” means a portion of vested equity awards is automatically sold to pay required taxes. In this case, Astera Labs used automatic open-market sales of Philip Mazzara’s shares from vested restricted stock units to fund tax withholding obligations, rather than requiring him to pay cash.

AI-generated analysis. How Rhea-AI works. Not financial advice.

Form 4 Insider Transactions: What Each Field Means →
See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google
Add on Google
SEC Form 4
FORM 4UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number:3235-0287
Estimated average burden
hours per response:0.5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.
1. Name and Address of Reporting Person*
Mazzara Philip
(Last)(First)(Middle)
C/O ASTERA LABS, INC.
2345 NORTH FIRST STREET
(Street)
SAN JOSE CALIFORNIA 95131
(City)(State)(Zip)
UNITED STATES
(Country)		2. Issuer Name and Ticker or Trading Symbol
Astera Labs, Inc. [ ALAB ] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director10% Owner
XOfficer (give title below)Other (specify below)
General Counsel and Secretary
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/18/2026		6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year)2A. Deemed Execution Date, if any (Month/Day/Year)3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeVAmount(A) or (D)Price
Common Stock05/18/2026S9,204D$235.36109,011D
Common Stock05/18/2026S(1)990D$235.4146(2)108,021D
Common Stock05/18/2026S(1)116D$233.1866(3)107,905D
Common Stock05/18/2026S(1)99D$232.808(4)107,806D
Common Stock05/18/2026S(1)387D$231.3126(5)107,419D
Common Stock05/18/2026S(1)186D$230.2814(6)107,233D
Common Stock05/18/2026S(1)55D$229.5364(7)107,178D
Common Stock05/18/2026S(1)275D$226.713(8)106,903D
Common Stock05/18/2026S(1)90D$225.7602(9)106,813D
Common Stock05/18/2026S(1)35D$225.0051(10)106,778D
Common Stock05/18/2026S(1)245D$223.7453(11)106,533D
Common Stock05/18/2026S(1)189D$222.2011(12)106,344D
Common Stock05/18/2026S(1)170D$221.0062(13)106,174D
Common Stock05/18/2026S(1)274D$220.2(14)105,900D
Common Stock05/18/2026S(1)356D$218.8679(15)105,544D
Common Stock05/18/2026S(1)364D$218.0567(16)105,180D
Common Stock05/18/2026S(1)646D$216.972(17)104,534D
Common Stock05/18/2026S(1)395D$216.3056(18)104,139D
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year)3A. Deemed Execution Date, if any (Month/Day/Year)4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year)7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Explanation of Responses:
1. Represents shares of the Issuer's Common Stock required to be sold by the Reporting Person to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units previously granted to the Reporting Person. Such sales were automatic and mandated by an election of the Issuer made in advance of the vesting event to require the satisfaction of tax withholding obligations to be funded by a "sell to cover", and does not represent a discretionary trade by the Reporting Person.
2. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $235.9400 to $235.3600, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
3. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $233.9800 to $233.1600, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
4. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $232.9700 to $232.7700, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
5. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $231.9000 to $230.9300, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
6. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $230.79000 to $229.9400, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
7. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $229.7900 to $228.9350, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
8. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $227.2000 to $226.2800, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
9. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $226.1800 to $225.2700, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
10. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $225.0500 to $224.5000, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
11. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $223.9900 to $223.3000, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
12. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $222.6400 to $221.6800, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
13. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $221.6400 to $220.6500, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
14. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $220.5200 to $219.7000, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
15. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $219.5100 to $218.5300, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
16. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $218.5000 to $217.5400, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
17. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $217.5000 to $216.5200, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
18. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $216.4900 to $216.1000, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
Remarks:
/s/ Philip Mazzara05/20/2026
** Signature of Reporting PersonDate
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

Source: View Original Filing on SEC EDGAR

Keep reading

More on ALAB

Trending in the feed

Open the live feed

From our desk