Summary
Latest filing:
William Jl Rieflin files SEC Form 4 reports at Lyell Immunopharma, Inc. (LYEL). 2 SEC Form 4 filings on record going back to 2025, most recently on 12 June 2026.
Trading pattern
InsiderAlpha's records for William Jl Rieflin go back to 2025: 2 primary Form 4 filings, an average of 1.0 per year. No recorded transaction carries a Rule 10b5-1 plan flag. An absent flag does not establish whether a transaction was pre-arranged or discretionary.
Other insiders active in the same stocks
Insiders who reported open-market trades in the last 12 months at the companies William Jl Rieflin files at. Multiple unrelated insiders buying the same stock within a short window, cluster buying, has historically been one of the strongest Form 4 signals.
- ARCH Venture Fund XIII, L.P. - $12.50M in LYEL purchases and sales in the last 12 months
- ARCH Venture Partners IX, LLC - $12.50M in LYEL purchases and sales in the last 12 months
- Lynn Seely - $353K in LYEL purchases and sales in the last 12 months
- Gary K. Lee - $72K in LYEL purchases and sales in the last 12 months
- Stephen J. Hill - $51K in LYEL purchases and sales in the last 12 months
- David Shook - $31K in LYEL purchases and sales in the last 12 months
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Frequently asked questions
Who is William Jl Rieflin?
William Jl Rieflin is a corporate insider of Lyell Immunopharma, Inc. (LYEL). InsiderAlpha holds 2 primary Form 4 filings for them, the earliest from 2025, updated as new SEC EDGAR filings are processed.
When did William Jl Rieflin last file a Form 4?
The most recent primary Form 4 on record is dated 12 June 2026, one of 2 filings going back to 2025.