Heflin Adam C 4

What Happened
Adam C. Heflin, EVP & Chief Nuclear Officer at Arizona Public Service (a Pinnacle West subsidiary), had 22,157 performance-based Pinnacle West shares vest on 2026-03-18 (acquired at $0). On the same date he sold 2,642 shares at $100.92 each for $266,631 and surrendered 8,364 shares (valued at $100.92 each, ~$844,095) to the company to satisfy tax withholding obligations.

Key Details

• Transaction date: 2026-03-18; Filing date: 2026-03-20 (timely filing).
• Award/Grant (A): 22,157 shares vested at $0.00.
• Disposition to issuer (D): 2,642 shares sold at $100.92 ($266,631).
• Tax withholding (F): 8,364 shares surrendered at $100.92 (~$844,095) to cover tax liability.
• Shares owned after the transactions: not specified in this Form 4 filing.
• Footnotes: F1—shares vested from a 2023 performance share grant tied to total shareholder return, EPS growth, clean megawatts installed, and dividend-equivalent rights; F2—cash settlement related to dividend equivalents; F3—company retained shares to meet tax withholding; the recipient retained the remaining vested shares.

Context
This was primarily a vesting of performance shares, with a small open-market sale and routine share withholding to satisfy taxes. Sales to cover tax withholding or cash-settled dividend equivalents are common and typically administrative rather than a directional bet on the stock. This was not an option exercise in the traditional sense — it was the settlement/vesting of performance shares.