Mastec MTZ Insider Ownership

Updated Oct 16, 2026

Over the past year, MTZ insiders sold $6.32 million of stock (18.88K shares) on the open market and bought none.

• Behind Mastec's open-market sales in the past 12 months were 4 insiders, and no insider bought.
• The largest open-market sales of MTZ in the past 12 months were by Ernst N. Csiszar (Director), totaling $4.37 million (13K shares), most recently on June 3, 2026.
• In transactions other than open-market trades, Mastec insiders received 71.65K shares in stock awards and gave up 61.55K shares to cover taxes or exercise prices over the past 12 months.
• Per Business Quant, MTZ insiders together hold 16.95Mn shares based on their latest Form 4 filings, up 0.01% from 16.95Mn shares at the end of Q2 2026 and down 0.06% from 16.96Mn shares at the end of Q3 2025.
• By type of ownership, MTZ insiders hold 49.12% of their shares directly (8.33Mn shares) and 50.88% indirectly (8.63Mn shares).
• Business Quant counts 14 insiders with holdings in Mastec stock, among the officers, directors and 10% owners who have filed a Form 4 in the past two years.
• Mastec's three largest insider shareholders, based on their latest Form 4 filings, are Jorge Mas (Director, 11.45Mn shares), Jose Ramon Mas (CEO, 4.96Mn shares) and Robert E. Apple (COO, 195.66K shares).
• Jorge Mas alone accounts for 67.52% of the shares held by Mastec insiders.
• Institutions held 74.01% of Mastec's outstanding shares in their Q2 2026 13F filings, insiders about 21.11% based on their latest Form 4 filings, and other investors, including the public, the remaining 4.88%.
• A total of 43 Form 4 filings with transactions in Mastec stock were made over the past 12 months, by 14 insiders.
• The insider holdings and trades above for Mastec reflect Form 4 filings through August 18, 2026.