MasTec (MTZ) director Ernst Csiszar sells 6,500 shares in open market

Rhea-AI Filing Summary

MasTec Inc. director Ernst N. Csiszar reported an open-market sale of 6,500 shares of Common Stock at an average price of $371.17 per share. After this transaction, he directly holds 10,816 MasTec shares, indicating he retained a substantial equity position following the sale.

Insider Trade Summary

Net Seller: 6,500 shares ($2,412,605)

Net Sell 1 txn

Insider Csiszar Ernst N

Role null

Sold 6,500 shs ($2.41M)

Type	Security	Shares	Price	Value
Sale	Common Stock	6,500	$371.17	$2.41M

Holdings After Transaction: Common Stock — 10,816 shares (Direct, null)

Footnotes (1)

Key Figures

Shares sold: 6,500 shares Sale price: $371.17 per share Shares held after transaction: 10,816 shares +1 more

4 metrics

Shares sold 6,500 shares Open-market sale of MasTec Common Stock

Sale price $371.17 per share Average price for the 6,500-share sale

Shares held after transaction 10,816 shares Director’s direct MasTec holdings post-transaction

Net shares sold 6,500 shares Net buy/sell direction reported as net-sell

Key Terms

Common Stock, open-market sale, Form 4, transaction code "S"

4 terms

Common Stock financial

"security_title: "Common Stock""

Common stock represents ownership shares in a company, giving investors a stake in its success and a say in important decisions through voting rights. It is the most common type of stock traded on markets and can provide income through dividends, as well as potential for value growth. For investors, holding common stock means sharing in the company’s profits and risks.

open-market sale financial

"transaction_action: "open-market sale""

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

Form 4 regulatory

"INSIDER FILING DATA (Form 4)"

Form 4 is a official document that company insiders, such as executives or major shareholders, file with regulators whenever they buy or sell company shares. It provides transparency about how those with inside knowledge are trading, helping investors see if insiders are confident in the company's prospects or may be selling for personal reasons. This information can influence investor decisions by revealing insiders' perspectives on the company's value.

transaction code "S" financial

"transaction_code_description: "Sale in open market or private transaction""

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Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED 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^*

Csiszar Ernst N

(Last) (First) (Middle)

1579 KATHWOOD DR.

(Street)

COLUMBIA SOUTH CAROLINA 29206

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
MASTEC INC [ MTZ ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
06/03/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form 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)
			Code	V	Amount	(A) or (D)	Price
Common Stock	06/03/2026		S		6,500	D	$371.17	10,816	D

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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

Remarks:

	\s\ Alberto de Cardenas For: Ernst Csiszar	06/05/2026
	** Signature of Reporting Person	Date
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)

FAQ

What insider transaction did MasTec (MTZ) disclose for Ernst N. Csiszar?

MasTec disclosed that director Ernst N. Csiszar executed an open-market sale of 6,500 shares of Common Stock. The transaction was reported on Form 4 and reflects a routine disposition of shares rather than an acquisition or option exercise.

How many MasTec (MTZ) shares did the director sell and at what price?

Ernst N. Csiszar sold 6,500 MasTec Common Stock shares at an average price of $371.17 per share. This was classified as an open-market sale transaction under code “S,” indicating a straightforward sale into the market.

How many MasTec (MTZ) shares does Ernst N. Csiszar hold after the sale?

Following the 6,500-share sale, Ernst N. Csiszar directly holds 10,816 MasTec Common Stock shares. This post-transaction balance shows he continues to maintain a meaningful ownership stake in the company after completing the reported disposition.

Was the MasTec (MTZ) insider trade a purchase or a sale?

The reported MasTec insider trade by Ernst N. Csiszar was a sale, not a purchase. It is coded “S” on Form 4 and described as an open-market sale of Common Stock, with no accompanying option exercise or other derivative transaction.

Did the MasTec (MTZ) Form 4 include any derivative or option exercises?

The Form 4 for Ernst N. Csiszar did not include any derivative or option exercises. All reported activity involved non-derivative Common Stock, and the derivative transaction count and exercise share totals in the summary are both listed as zero.