Stephen Mitchell Howell Jr.
Stephen Mitchell Howell Jr.: COO at Riot Platforms. What Stephen Mitchell Howell Jr. holds in an AI or semiconductor company tracked on Silicon Floor, from their SEC filings, broken down: the shares held and how, then any restricted shares, options or other rights declared.
Riot Platforms (RIOT)
Stephen Mitchell Howell Jr. holds 1.8M Riot Platforms shares (0.49% of the company), worth about $35.1M at the last price, according to the Form 4 of Aug 12, 2026.
- Shares held: 1.8M (0.49%), $35.1M — Held in their own name.
Declarations
- Riot Platforms (RIOT) — Form 4 of Aug 12, 2026 (COO): gift of 21,198; 1.8M shares after 0002025334-26-000010
- Riot Platforms (RIOT) — Form 4 of Jul 31, 2026 (COO): shares withheld for tax of 153,162 at $20.17; 1.9M shares after 0002025334-26-000008
- Riot Platforms (RIOT) — Form 4 of Jul 1, 2026 (COO): shares withheld for tax of 21,966 at $23.96; 2.0M shares after 0002025334-26-000006
- Riot Platforms (RIOT) — Form 4 of Jan 1, 2026 (COO): shares withheld for tax of 29,482 at $12.67; grant or award of 197,316; 2.0M shares after 0002025334-26-000002
- Riot Platforms (RIOT) — Form 4/A of Jul 1, 2025 (COO): shares withheld for tax of 20,345 at $11.27; 802,785 shares after 0002025334-25-000003
- Riot Platforms (RIOT) — Form 4 of Jul 1, 2025 (COO): shares withheld for tax of 20,345 at $11.27; grant or award of 221,827; 1.5M shares after 0001415889-25-019331
- Riot Platforms (RIOT) — Form 4 of Jul 1, 2024 (COO): shares withheld for tax of 3,188 at $9.95; grant or award of 125,628; 823,130 shares after 0001415889-24-019302
Sources: SEC Schedules 13D and 13G (stakes above 5%, which count everything a person votes or can acquire within 60 days) and Forms 3, 4 and 5 (the shares a director, officer or 10% owner holds, filed within two business days of each trade). Values at the last price.