Magnite, Inc. Form 4 Filings

Magnite, Inc. (MGNI) Chief Accounting Officer Sullivan Haas received an award of 24,641 restricted stock units on October 1, 2026, under the Amended and Restated 2014 Equity Incentive Plan. His reported direct common-stock holdings following the transaction were 97,554 shares.

The award vests in installments: 6,674 shares on November 15, 2027; 1,540 shares on each February 15, May 15, August 15, and November 15 thereafter until August 15, 2030; and 1,027 shares on November 15, 2030. Vesting is subject to continued service through each vesting date. The grant may be subject to accelerated vesting if employment ends under certain circumstances.

Magnite, Inc. (MGNI) Chief Financial Officer Brian Gephart acquired 64,682 restricted stock units on October 1, 2026. His reported direct position following the transaction was 167,010 shares. The grant is under the Amended and Restated 2014 Equity Incentive Plan. Vesting is scheduled in installments from November 15, 2027, through November 15, 2030, subject to continued service through each vesting date.

MAGNITE, INC. (MGNI) director Paul Caine reported selling 7,500 shares of common stock on September 17, 2026 at $26.50 per share in an open-market or private transaction. Following this sale, he directly holds 137,401 shares of MAGNITE common stock. The trade was effected pursuant to a Rule 10b5-1 trading plan adopted on August 20, 2025.

MAGNITE, INC. (MGNI) director Douglas S. Knopper sold Common Stock in an open-market transaction on September 17, 2026. He sold 37,337 shares at a weighted average price of $26.28 per share, with actual trade prices ranging from $26.00 to $26.50. Following this sale, he directly holds 51,136 shares of MAGNITE, INC. common stock. The sale was effected pursuant to a Rule 10b5-1 trading plan adopted on December 12, 2025.

MAGNITE, INC. (MGNI) Chief Technology Officer David Buonasera reported a sale of 1,165 shares of common stock on September 14, 2026 at $24.00 per share, in an open-market or private transaction. Following this sale, he directly holds 245,155 shares of MAGNITE common stock. The transaction was effected pursuant to a Rule 10b5-1 trading plan adopted on June 13, 2026.

MAGNITE, INC. (MGNI) director Robert F. Spillane exercised stock options for 10,363 shares of common stock on September 14, 2026 at an exercise price of $5.17 per share, then sold 10,363 shares of common stock the same day at a weighted average price of $23.76 per share. The options were fully vested and granted as compensation, and this exercise left no shares remaining under that option award.

MAGNITE, INC. (MGNI) executive Katie Seitz Evans, President, Product & Operations, reported selling 13,997 shares of common stock on September 11, 2026 at $24.00 per share in an open-market or private transaction. After this sale, she directly holds 441,800 shares of Magnite common stock. The transaction was effected under a Rule 10b5-1 trading plan adopted on June 8, 2026.

MAGNITE, INC. (MGNI) reported that Chief Legal Officer Aaron Salt sold 40,000 shares of common stock on September 10, 2026 in an open-market transaction at a weighted average price of $23.41 per share. The sale was effected pursuant to a Rule 10b5-1 trading plan adopted on June 11, 2026, and Salt now directly holds 224,389 shares of Magnite common stock.

MAGNITE, INC. (MGNI) director Paul Caine reported selling 5,000 shares of common stock on September 10, 2026 in an open-market transaction at a weighted average price of $23.53 per share, under a Rule 10b5-1 trading plan adopted on August 20, 2025. After this sale, he directly holds 144,901 shares of MAGNITE common stock. The shares were sold in multiple trades at prices between $23.22 and $23.63 per share.

MAGNITE, INC. (MGNI) reported that President, Product & Operations Katie Seitz Evans exercised employee stock options for 13,546 shares of common stock at $5.16 per share on September 8, 2026, then sold 32,285 shares that day at a weighted average price of $23.63, and sold an additional 11,100 shares on September 9, 2026 at a weighted average price of $23.46. All reported trades were made under a Rule 10b5-1 trading plan adopted on June 8, 2026.

MAGNITE, INC. (MGNI) reported that its Chief Technology Officer, David Buonasera, sold a total of 6,414 shares of common stock in two open market or private transactions under a Rule 10b5-1 trading plan. The sales occurred on September 1, 2026 and September 2, 2026 at prices of $23.42 and $25.00 per share, respectively.

MAGNITE, INC. (MGNI) director Sarah Patricia Harden reported two open-market sales of common stock under a Rule 10b5-1 trading plan adopted on May 27, 2026. She sold 18,436 shares on August 28, 2026 at $24.00 per share and 30,550 shares on August 26, 2026 at a weighted average price of $23.31 per share, with the latter sale executed in multiple trades at prices ranging from $23.09 to $23.52 per share.

MAGNITE, INC. (MGNI) reported that Chief Technology Officer David Buonasera had 8,102 shares of common stock withheld on August 15, 2026 at $24.73 per share. The shares were a non-discretionary forfeiture to cover tax withholding obligations tied to vesting restricted stock units, leaving him with 252,734 shares held directly.

MAGNITE, INC. (MGNI) reported an insider tax-related share disposition by officer Katie Seitz Evans, President, Product & Operations. On 2026-08-15, 11,204 shares of common stock were forfeited on a non-discretionary basis to cover tax withholding obligations tied to vesting restricted stock units. Following this withholding transaction, Evans directly holds 485,636 shares of Magnite common stock.

MAGNITE, INC. (MGNI) reported that Chief Legal Officer Aaron Salt had 5,627 shares of common stock withheld on 2026-08-15 at $24.73 per share. The shares were non-discretionarily forfeited to cover tax withholding obligations arising from the vesting of restricted stock units, pursuant to an arrangement mandated by the company. After this tax-withholding disposition, Salt directly holds 264,389 shares of MAGNITE common stock.

MAGNITE, INC. (MGNI) disclosed that Chief Accounting Officer Brian Gephart had 3,789 shares of common stock withheld on 2026-08-15 under a non-discretionary arrangement mandated by the company to cover tax withholding obligations arising from the vesting of restricted stock units. The shares were valued at $24.73 per share for this purpose, and Gephart now holds 102,328 shares of Magnite common stock directly.

MAGNITE, INC. (MGNI) reported that CEO and director Michael G. Barrett had 10,404 shares of common stock withheld on 2026-08-15 at $24.73 per share. According to the company’s arrangement, these shares were non-discretionarily forfeited to cover tax withholding obligations on vesting restricted stock units, leaving Barrett with 392,670 directly held shares afterward.

MAGNITE, INC. (MGNI) reported an insider equity-related transaction by its Chief Financial Officer, David Day. On 2026-08-15, 14,170 shares of common stock were forfeited at $24.73 per share to satisfy tax withholding obligations tied to the vesting of restricted stock units, under a non-discretionary arrangement mandated by the company. After this tax-withholding disposition, Day directly holds 452,861 shares of MAGNITE common stock.

MAGNITE, INC. (MGNI) director Paul Caine reported selling 7,500 shares of common stock on August 14, 2026, at $25.00 per share in an open-market or private transaction. The sale was effected pursuant to a Rule 10b5-1 trading plan adopted on August 20, 2025, and Caine now directly holds 149,901 shares.

MAGNITE, INC. (MGNI) reported insider transactions by Sean Patrick Buckley, President, Revenue & Market Strategy. On August 18, 2026, he sold 2,759 shares of common stock at $25.00 per share, and on August 17, 2026, he sold 8,271 shares at a weighted average price of $24.31 per share. On August 15, 2026, 11,715 shares were disposed of to satisfy tax withholding obligations related to vesting of restricted stock units. The sales on August 17 and 18 were effected pursuant to a Rule 10b5-1 trading plan adopted on September 10, 2025.

MAGNITE, INC. chief financial officer David Day reported a bona fide gift of 26,258 shares of Common Stock on August 13, 2026. The gift was recorded at $0.00 per share. Following this disposition, Day directly holds 467,031 shares of Common Stock. The transaction was not marked as being made under a Rule 10b5-1 trading plan.

Magnite, Inc. officer Brian Gephart, the Chief Accounting Officer, reported a sale of common stock. On 2026-08-10, he sold 12,479 shares of Magnite common stock in an open market or private transaction at a weighted average price of $24.68 per share, with actual prices ranging from $24.68 to $24.71. Following this transaction, he directly holds 106,117 shares of Magnite common stock.

MAGNITE, INC. director Rachel Lam reported a sale of 10,000 shares of common stock on 2026-08-10 in a non-derivative transaction. The sale was executed at a weighted average price of $24.16 per share, with individual trades ranging from $24.11 to $24.20. Following this sale, Lam directly holds 230,620 shares of MAGNITE common stock.

MAGNITE, INC. director Paul Caine reported selling 5,000 shares of common stock on August 10, 2026 in an open-market transaction. The sale was executed under a Rule 10b5-1 trading plan adopted on August 20, 2025. The weighted average sale price was $24.35 per share, with individual trades executed between $24.07 and $24.91. Following this transaction, Caine directly holds 157,401 shares of MAGNITE common stock.

MAGNITE, INC. executive Sean Patrick Buckley, President, Revenue & Market Strategy, exercised 28,703 stock options at $13.90 per share on August 6, 2026, acquiring the same number of common shares, then sold 67,179 shares at prices from $23.00 to $25.09. Following the exercise, 57,405 stock options remain outstanding and are fully vested and immediately exercisable. All reported transactions were effected under a Rule 10b5-1 trading plan adopted on September 10, 2025.

MAGNITE, INC. director Douglas S. Knopper sold 37,337 shares of common stock on August 6, 2026 at $22.72 per share. The sale was executed under a pre-arranged Rule 10b5-1 trading plan adopted on December 12, 2025, and he now directly owns 88,473 shares.

MAGNITE, INC. Chief Technology Officer David Buonasera reported selling 7,649 shares of common stock on August 6, 2026 in three open-market transactions under a Rule 10b5-1 trading plan adopted on September 11, 2025. Sale prices ranged from $22.72 to $25.00 per share.

Magnite, Inc. executive Katie Seitz Evans, President, Product & Operations, exercised employee stock options for 20,000 shares of common stock at an exercise price of $5.1600 per share on August 6, 2026, then sold 20,000 shares at $24.0000 per share. The options were fully vested, granted as compensation, and the exercise and sale were made under a Rule 10b5-1 trading plan adopted on August 28, 2025.

Magnite, Inc. CEO Michael G. Barrett exercised stock options covering 293,968 shares of common stock at an exercise price of $5.80 per share and sold the same number of shares at $22.72 per share on August 6, 2026. The options were granted as compensation, were fully vested and immediately exercisable, and were due to expire on March 17, 2027. The exercise and subsequent sale were carried out under a Rule 10b5-1 trading plan adopted on March 13, 2026.

Magnite CEO Michael G. Barrett exercised employee stock options for 38,596 shares at $5.80 per share and sold 38,596 common shares at a weighted average price of $20.35 on July 15, 2026 under a Rule 10b5-1 plan adopted March 13, 2026. After these trades, he holds 403,074 common shares and 293,968 remaining stock options expiring March 17, 2027.

Magnite, Inc. director Paul Caine reported an open-market sale of 5,000 shares of common stock on July 10, 2026 at a weighted average price of $20.64 per share, with individual trades between $20.31 and $21.25. The sale was executed under a pre-arranged Rule 10b5-1 trading plan adopted on August 20, 2025, and Caine now directly owns 162,401 shares of Magnite common stock.

Magnite, Inc. Chief Technology Officer David Buonasera reported an open-market sale of 1,224 shares of Common Stock at $21.00 per share. After this transaction, he directly holds 268,485 shares.

The sale was executed under a pre-arranged Rule 10b5-1 trading plan adopted on September 11, 2025, indicating it was scheduled in advance rather than timed opportunistically.

MAGNITE, INC. officer Sean Patrick Buckley reported an open-market sale of 19,233 shares of common stock on July 7, 2026. The shares were sold at a weighted average price of $21.03 per share, in multiple trades between $21.00 and $21.16.

After this transaction, Buckley directly holds 354,281 shares of Magnite common stock. The sale was carried out under a pre-arranged Rule 10b5-1 trading plan that Buckley adopted on September 10, 2025, indicating the trades were scheduled in advance.

MAGNITE, INC. Chief Technology Officer David Buonasera sold 9,376 shares of Common Stock in an open-market transaction at $20.00 per share. After the sale, he directly holds 269,709 shares. The transaction was carried out under a pre-arranged Rule 10b5-1 trading plan adopted on September 11, 2025.

MAGNITE, INC. CEO Michael G. Barrett reported an option exercise and related share sale in Common Stock. He exercised options for 75,000 shares at $5.80 per share and sold 75,000 shares in an open-market transaction at $19.50 per share.

Following these transactions, Barrett holds 403,074 shares of Common Stock directly. The exercise and subsequent sale were carried out under a pre-arranged Rule 10b5-1 trading plan, indicating the trades were scheduled in advance as part of a structured liquidity plan.

Magnite, Inc. officer Sean Patrick Buckley reported an open-market sale of 19,233 shares of Common Stock at $19.00 per share. After this transaction, he directly holds 373,514 shares, indicating he retains a substantial equity position. The filing notes the sale was executed under a pre-arranged Rule 10b5-1 trading plan adopted on September 10, 2025, suggesting the trade was scheduled in advance rather than timed opportunistically.

MAGNITE, INC. director Douglas S. Knopper reported an open-market sale of 37,337 shares of common stock on June 16, 2026 at a weighted average price of $18.10 per share, with individual trade prices ranging from $18.00 to $18.25.

The transaction was executed under a pre-arranged Rule 10b5-1 trading plan adopted on December 12, 2025. Following this sale, Knopper directly holds 125,810 shares of Magnite common stock.

MAGNITE, INC. Chief Technology Officer David Buonasera reported open-market sales of company Common Stock over three consecutive days. He sold 1,057 shares at $17.00, 11,233 shares at $18.00, and 1,409 shares at $19.00, totaling 13,699 shares.

Following these transactions, Buonasera directly holds 279,085 shares of Magnite common stock. The filing notes that the reported transactions were executed under a pre-arranged Rule 10b5-1 trading plan adopted on September 11, 2025, indicating they were scheduled in advance rather than timed discretionarily.

Magnite, Inc. CEO Michael G. Barrett exercised stock options and sold shares in paired transactions disclosed on this Form 4. On June 15, 2026, he exercised options to acquire 178,596 shares of common stock at a $5.80 exercise price and sold 178,596 shares in open‑market transactions at a weighted average price of $16.59, with individual trades ranging from $15.945 to $16.93. On June 16, 2026, he exercised options to acquire an additional 100,000 shares at $5.80 and sold 100,000 shares at $17.50 per share. The filing reports that these exercises and subsequent sales were made pursuant to a pre‑arranged Rule 10b5‑1 trading plan adopted on March 13, 2026. Following the transactions, Barrett directly holds 403,074 shares of Magnite common stock, with the reported options fully vested and immediately exercisable before their stated expiration date of March 17, 2027.

Caine Paul reported acquisition or exercise transactions in this Form 4 filing.

MAGNITE, INC. director Paul Caine received a grant of 13,798 shares of common stock in the form of restricted stock units as compensation for services. These units vest in full on the earliest of June 8, 2027, the 2027 annual stockholders’ meeting, or a change of control of the company. After this award, Caine holds 167,401 shares of common stock directly.

MAGNITE, INC. director Diane Yu received an equity award of 13,798 shares of common stock in the form of restricted stock units as compensation for services. The award was granted at a price of $0.00 per share and increases her direct holdings to 81,279 shares.

The restricted stock units vest in full on the earliest of June 8, 2027, the date of Magnite’s 2027 annual stockholder meeting, or a change of control of the company. This filing reflects a routine, compensation-related acquisition rather than an open-market purchase or sale.

Spillane Robert F reported acquisition or exercise transactions in this Form 4 filing.

MAGNITE, INC. director Robert F. Spillane reported an award of 13,798 shares of Common Stock in the form of restricted stock units granted as compensation for services. These units vest in full on the earliest of June 8, 2027, the company’s 2027 annual stockholders’ meeting, or a change of control of the company. Following this award, Spillane directly holds 57,715 shares of Common Stock.

Harden Sarah Patricia reported acquisition or exercise transactions in this Form 4 filing.

Magnite, Inc. director Sarah Patricia Harden received a grant of 13,798 shares of common stock in the form of restricted stock units as compensation for services. These units vest in full on the earliest of June 8, 2027, the 2027 annual stockholders’ meeting, or a change of control. After this award, she directly holds 163,737 shares of Magnite common stock.

MAGNITE, INC. director Douglas S. Knopper reported both an equity award and a share sale. On June 8, 2026, he received 13,798 shares of Common Stock as a grant at $0.00 per share, representing restricted stock units that vest in full on the earliest of June 8, 2027, the 2027 annual stockholder meeting date, or a change of control. On June 10, 2026, he sold 10,766 Common Stock shares in an open-market transaction at a weighted average price of $15.73 per share under a Rule 10b5-1 trading plan adopted on December 12, 2025, with individual trade prices ranging from $15.29 to $15.90. Following these transactions, he directly holds 163,147 Common Stock shares.

Rossman James reported acquisition or exercise transactions in this Form 4 filing.

MAGNITE, INC. director James Rossman received a grant of 13,798 shares of common stock in the form of restricted stock units as compensation for services. These units were awarded at no cash cost to him and increase his direct holdings to 107,477 shares after the transaction.

The restricted stock units vest in full on the earliest of June 8, 2027, the date of Magnite’s 2027 annual stockholders’ meeting, or a change of control of the company. Until vesting, the award remains subject to these time- and event-based conditions.

MAGNITE, INC. director Rachel Lam received a grant of 13,798 shares of common stock in the form of restricted stock units as compensation for services. These units vest in full on the earliest of June 8, 2027, the 2027 annual stockholder meeting date, or a change of control of the company.

Following this award, Lam directly owns 240,620 shares of common stock. The transaction is classified as a grant or award acquisition rather than an open-market purchase or sale.

MAGNITE, INC. director David T. Pearson reported both an equity award and a share sale. He received 13,798 restricted stock units as compensation, which vest in full on the earliest of June 8, 2027, the 2027 annual stockholder meeting, or a change of control.

On June 10, 2026, he sold 10,766 shares of Common Stock in open-market transactions at a weighted average price of $15.65 per share, under a pre-arranged Rule 10b5-1 trading plan. Following these transactions, he directly owns 79,001 shares of Magnite common stock.

Magnite, Inc.'s Chief Technology Officer David Buonasera reported an open-market sale of 1,409 shares of Common Stock at $15.00 per share. After this transaction, he directly holds 292,784 shares. The sale was executed under a pre-arranged Rule 10b5-1 trading plan adopted on September 11, 2025.

MAGNITE, INC. director Robert F. Spillane reported an open-market sale of 10,000 shares of common stock on May 19, 2026 at a weighted average price of $13.33 per share. After this transaction, he directly owns 43,917 common shares.

The filing notes that the shares were sold in multiple trades at prices ranging from $13.32 to $13.355 per share, with full trade-by-trade details available upon request to the company, its security holders, or the SEC staff.