SEC Insider Transactions from York Charles N II.

Last updated: 2026-03-14 11:50 UTC | Total transactions: 92

York Charles N II, COO and CFO of Day One Biopharmaceuticals ($DAWN), sold shares on the open market four times in the last 365 days for a total of about $161 thousand. His most recent sale occurred on February 17, 2026. These sales rank in 8,852nd place among 11,678 individual insiders, compared to an average sale value of $8.6 million across about six transactions per insider. He made no open market purchases during this period.

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Transaction Date Company Ticker Insider Name Title Transaction Type Security Shares Price Shares Owned Following Total Shares Outstanding % of Owned % of Outstanding
Feb. 15, 2026 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Restricted Stock Unit (RSU) 6625 $0.00 46,375.0000 103,381,315 12.50% 0.01%
Feb. 15, 2026 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Restricted Stock Unit (RSU) 2250 $0.00 6,750.0000 103,381,315 25.00% 0.00%
Feb. 17, 2026 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO S Common Stock 6065 $11.60 312,025.0000 103,381,315 1.91% 0.01%
Feb. 15, 2026 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Common Stock 7875 $0.00 318,090.0000 103,381,315 2.54% 0.01%
Feb. 15, 2026 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Common Stock 6625 $0.00 310,215.0000 103,381,315 2.18% 0.01%
Feb. 15, 2026 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Common Stock 6625 $0.00 303,590.0000 103,381,315 2.23% 0.01%
Feb. 15, 2026 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Common Stock 2250 $0.00 296,965.0000 103,381,315 0.76% 0.00%
Feb. 15, 2026 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Restricted Stock Unit (RSU) 7875 $0.00 118,125.0000 103,381,315 6.25% 0.01%
Feb. 15, 2026 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Restricted Stock Unit (RSU) 6625 $0.00 72,875.0000 103,381,315 8.33% 0.01%
Jan. 30, 2026 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO A Restricted Stock Units 126000 $0.00 126,000.0000 103,381,315 9999.99% 0.12%
Jan. 30, 2026 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO A Stock Option (right to buy Common Stock) 188000 $0.00 188,000.0000 103,381,315 9999.99% 0.18%
Nov. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Common Stock 6625 $0.00 292,152.0000 103,381,315 2.32% 0.01%
Nov. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Common Stock 6625 $0.00 298,777.0000 103,381,315 2.27% 0.01%
Nov. 17, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO S Common Stock 4062 $8.91 294,715.0000 103,381,315 1.36% 0.00%
Nov. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Common Stock 1375 $0.00 283,277.0000 103,381,315 0.49% 0.00%
Nov. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Restricted Stock Unit (RSU) 2250 $0.00 9,000.0000 103,381,315 20.00% 0.00%
Nov. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Restricted Stock Unit (RSU) 6625 $0.00 53,000.0000 103,381,315 11.11% 0.01%
Nov. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Restricted Stock Unit (RSU) 6625 $0.00 79,500.0000 103,381,315 7.69% 0.01%
Nov. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Restricted Stock Unit (RSU) 1375 $0.00 0.0000 103,381,315 100.00% 0.00%
Nov. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Common Stock 2250 $0.00 285,527.0000 103,381,315 0.79% 0.00%
Nov. 6, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO A Stock Option (right to buy Common Stock) 162000 $0.00 162,000.0000 103,381,315 9999.99% 0.16%
Nov. 6, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO A Stock Option (right to buy Common Stock) 162000 $0.00 162,000.0000 103,381,315 9999.99% 0.16%
Nov. 6, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO D Stock Option (right to buy Common Stock) 162000 $0.00 0.0000 103,381,315 100.00% 0.16%
Nov. 6, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO A Stock Option (right to buy Common Stock) 116000 $0.00 116,000.0000 103,381,315 9999.99% 0.11%
Nov. 6, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO D Stock Option (right to buy Common Stock) 116000 $0.00 0.0000 103,381,315 100.00% 0.11%
Nov. 6, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO A Stock Option (right to buy Common Stock) 151000 $0.00 151,000.0000 103,381,315 9999.99% 0.15%
Nov. 6, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO D Stock Option (right to buy Common Stock) 151000 $0.00 0.0000 103,381,315 100.00% 0.15%
Nov. 6, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO A Stock Option (right to buy Common Stock) 497667 $0.00 497,667.0000 103,381,315 9999.99% 0.48%
Nov. 6, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO D Stock Option (right to buy Common Stock) 497667 $0.00 0.0000 103,381,315 100.00% 0.48%
Nov. 6, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO D Stock Option (right to buy Common Stock) 162000 $0.00 0.0000 103,381,315 100.00% 0.16%
Aug. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Restricted Stock Unit (RSU) 6625 $0.00 59,625.0000 93,234,195 10.00% 0.01%
Aug. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Restricted Stock Unit (RSU) 2250 $0.00 11,250.0000 93,234,195 16.67% 0.00%
Aug. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Restricted Stock Unit (RSU) 1375 $0.00 1,375.0000 93,234,195 50.00% 0.00%
Aug. 18, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO S Common Stock 4106 $6.77 278,000.0000 93,234,195 1.46% 0.00%
Aug. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Common Stock 6625 $0.00 282,106.0000 93,234,195 2.40% 0.01%
Aug. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Common Stock 1375 $0.00 266,606.0000 93,234,195 0.52% 0.00%
Aug. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Common Stock 6625 $0.00 275,481.0000 93,234,195 2.46% 0.01%
Aug. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Common Stock 2250 $0.00 268,856.0000 93,234,195 0.84% 0.00%
Aug. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO and CFO M Restricted Stock Unit (RSU) 6625 $0.00 86,125.0000 93,234,195 7.14% 0.01%
May 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 6625 $0.00 262,888.0000 93,234,195 2.59% 0.01%
May 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 1375 $0.00 254,013.0000 93,234,195 0.54% 0.00%
May 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 2250 $0.00 256,263.0000 93,234,195 0.89% 0.00%
May 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 6625 $0.00 269,513.0000 93,234,195 2.52% 0.01%
May 16, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY S Common Stock 4282 $6.26 265,231.0000 93,234,195 1.59% 0.00%
May 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 1375 $0.00 2,750.0000 93,234,195 33.33% 0.00%
May 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 2250 $0.00 13,500.0000 93,234,195 14.29% 0.00%
May 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 6625 $0.00 66,250.0000 93,234,195 9.09% 0.01%
May 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 6625 $0.00 92,750.0000 93,234,195 6.67% 0.01%
Feb. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 6625 $0.00 99,375.0000 93,234,195 6.25% 0.01%
Feb. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 1375 $0.00 241,508.0000 93,234,195 0.57% 0.00%
Feb. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 2250 $0.00 243,758.0000 93,234,195 0.93% 0.00%
Feb. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 6625 $0.00 250,383.0000 93,234,195 2.72% 0.01%
Feb. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 6625 $0.00 257,008.0000 93,234,195 2.65% 0.01%
Feb. 18, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY S Common Stock 4370 $11.96 252,638.0000 93,234,195 1.70% 0.00%
Feb. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 1375 $0.00 4,125.0000 93,234,195 25.00% 0.00%
Feb. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 2250 $0.00 15,750.0000 93,234,195 12.50% 0.00%
Feb. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 6625 $0.00 72,875.0000 93,234,195 8.33% 0.01%
Jan. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY A Stock Option (right to buy Common Stock) 162000 $0.00 162,000.0000 93,234,195 9999.99% 0.17%
Jan. 15, 2025 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY A Restricted Stock Units 106000 $0.00 106,000.0000 93,234,195 9999.99% 0.11%
Nov. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 2250 $0.00 18,000.0000 96,937,759 11.11% 0.00%
Nov. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 1375 $0.00 233,860.0000 96,937,759 0.59% 0.00%
Nov. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 2250 $0.00 236,110.0000 96,937,759 0.96% 0.00%
Nov. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 6625 $0.00 242,735.0000 96,937,759 2.81% 0.01%
Nov. 18, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY S Common Stock 2602 $13.21 240,133.0000 96,937,759 1.07% 0.00%
Nov. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 1375 $0.00 5,500.0000 96,937,759 20.00% 0.00%
Nov. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 6625 $0.00 79,500.0000 96,937,759 7.69% 0.01%
Aug. 16, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY S Common Stock 2633 $14.00 232,485.0000 79,773,004 1.12% 0.00%
Aug. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 6625 $0.00 86,125.0000 79,773,004 7.14% 0.01%
Aug. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 2250 $0.00 20,250.0000 79,773,004 10.00% 0.00%
Aug. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 1375 $0.00 6,875.0000 79,773,004 16.67% 0.00%
Aug. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 6625 $0.00 235,118.0000 79,773,004 2.90% 0.01%
Aug. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 2250 $0.00 228,493.0000 79,773,004 0.99% 0.00%
Aug. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 1375 $0.00 226,243.0000 79,773,004 0.61% 0.00%
May 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 2250 $0.00 22,500.0000 79,773,004 9.09% 0.00%
May 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 1375 $0.00 218,668.0000 79,773,004 0.63% 0.00%
May 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 2250 $0.00 220,918.0000 79,773,004 1.03% 0.00%
May 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 6625 $0.00 227,543.0000 79,773,004 3.00% 0.01%
May 16, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY S Common Stock 2675 $16.08 224,868.0000 79,773,004 1.18% 0.00%
May 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 1375 $0.00 8,250.0000 79,773,004 14.29% 0.00%
May 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 6625 $0.00 92,750.0000 79,773,004 6.67% 0.01%
May 1, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY S Common Stock 52183 $17.89 225,571.0000 79,773,004 18.79% 0.07%
May 3, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY S Common Stock 8078 $17.85 217,293.0000 79,773,004 3.58% 0.01%
May 2, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY S Common Stock 200 $17.90 225,371.0000 79,773,004 0.09% 0.00%
Feb. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 2250 $0.00 24,750.0000 79,773,004 8.33% 0.00%
Feb. 16, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY S Common Stock 2666 $15.25 277,754.0000 79,773,004 0.95% 0.00%
Feb. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 6625 $0.00 280,420.0000 79,773,004 2.42% 0.01%
Feb. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 2250 $0.00 273,795.0000 79,773,004 0.83% 0.00%
Feb. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Common Stock 1375 $0.00 271,545.0000 79,773,004 0.51% 0.00%
Feb. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 6625 $0.00 99,375.0000 79,773,004 6.25% 0.01%
Feb. 15, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO AND SECRETARY M Restricted Stock Unit (RSU) 1375 $0.00 9,625.0000 79,773,004 12.50% 0.00%
Jan. 5, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO and Secretary A Restricted Stock Units 106000 $0.00 106,000.0000 79,773,004 9999.99% 0.13%
Jan. 5, 2024 Day One Biopharmaceuticals, Inc. $DAWN York Charles N II COO, CFO and Secretary A Stock Option (right to buy Common Stock) 162000 $0.00 162,000.0000 79,773,004 9999.99% 0.20%