Wednesday, October 28, 2026
Data from SEC filings, checked daily
Public filings, plainly told
WallStPal · PDF guide
LYEL Insider Trading: Insider Buys and Sells · https://wallstpal.com/stock/lyel/insider-trading/ · saved 2026-10-28

About this page

Insider trades reported on SEC Form 4: when the people who run a company buy or sell its shares with their own money.

How to read it

Form 4
The form a company insider (officer, director or owner of more than 10%) must file with the SEC within two business days of buying or selling the company's shares.
Buy (P) and Sell (S)
Open-market purchases and sales. Gifts, option exercises and automatic tax withholding are left out because they say little about what the insider thinks.
Value
Shares times price, as reported on the filing.
10b5-1
A trade made under a plan set up in advance. Planned sales are common and usually say less than an unplanned purchase.
Late filing
A Form 4 filed more than two business days after the trade.
Vs. S&P 500
How the stock did after the trade minus how the overall market did in the same weeks.

A real example

In January 2016, when bank stocks were falling, JPMorgan Chase CEO Jamie Dimon bought 500,000 JPMorgan shares with his own money, worth about $26 million. His Form 4 made the purchase public within days, and investors read it as a strong sign of confidence.

Explain it like I'm 13

If the coach of a team bets his own allowance that his team will win, that tells you something. A Form 4 is the note a company boss must hand in whenever he buys or sells his own company's shares, so everyone can see it.

Data from public SEC filings and congressional reports. Information, not investment advice. Check every number against the filing linked on the page.

Summarize with AIChatGPTClaudePerplexityGoogle AIGrokCopilot
Insider tradingForm 4

Lyell Immunopharma, Inc. (LYEL) Insider Trading

15 open-market trades reported since Jun 15, 2026: 0 purchases worth $0 and 15 sales worth $231K.

By insider

InsiderRoleBuysBoughtSellsSoldLatest
Jarrad Mattieu AguirreChief Medical Officer0$01$4KOct 13, 2026
David ShookChief Medical Officer0$01$6KSep 10, 2026
Lynn SeelyCEO0$03$162KAug 25, 2026
Gary K. LeeChief Scientific Officer0$03$27KAug 25, 2026
Stephen J. HillCOO0$03$18KAug 25, 2026
Veronica Sanchez BulisVP0$02$13KAug 11, 2026
Innovative Cellular Therapeutics Holdings Ltd10% owner0$02$274Jul 20, 2026

All trades

LYEL insider trades
FiledTradedInsiderRoleTypeSharesPrice ($)ValueHolding3 mo. afterFiling
Oct 13Oct 12Jarrad Mattieu AguirreChief Medical OfficerChief Medical Officer▼ SELL4228.63$4K−2.1%Form 4 ↗
Sep 10Sep 10David ShookChief Medical OfficerChief Medical Officer▼ SELL50012.70$6K−2.4%Form 4 ↗
Aug 25Aug 21Lynn SeelyCEOCEO▼ SELL9,58915.54$149K−13%Form 4 ↗
Aug 25Aug 21Gary K. LeeChief Scientific OfficerChief Scientific Officer▼ SELL1,45715.54$23K−8.2%Form 4 ↗
Aug 25Aug 21Stephen J. HillCOOCOO▼ SELL98915.54$15K−5.6%Form 4 ↗
Aug 11Aug 10Veronica Sanchez BulisVPVP▼ SELL62114.34$9K−4.0%Form 4 ↗
Aug 11Aug 10Lynn SeelyCEOCEO▼ SELL39014.34$6K−0.5%Form 4 ↗
Aug 11Aug 10Gary K. LeeChief Scientific OfficerChief Scientific Officer▼ SELL13114.34$2K−0.7%Form 4 ↗
Aug 11Aug 10Stephen J. HillCOOCOO▼ SELL8914.34$1K−0.5%Form 4 ↗
Jul 20Jul 17Innovative Cellular Therapeutics Holdings Ltd10% owner10% owner▼ SELL10b5-11013.70$137+0.0%Form 4 ↗
Jul 17Jul 16Innovative Cellular Therapeutics Holdings Ltd10% owner10% owner▼ SELL10b5-11013.70$137+0.0%Form 4 ↗
Jun 15May 11Lynn SeelyCEOCEO▼ SELL38818.91$7K−0.5%Form 4 ↗
Jun 15May 11Veronica Sanchez BulisVPVP▼ SELL21718.91$4K−1.4%Form 4 ↗
Jun 15May 11Gary K. LeeChief Scientific OfficerChief Scientific Officer▼ SELL13018.92$2K−0.7%Form 4 ↗
Jun 15May 11Stephen J. HillCOOCOO▼ SELL8918.92$2K−0.5%Form 4 ↗
Source: SEC Form 4 filings, retrieved Oct 28, 2026. How we read filings