# Lyell Immunopharma, Inc. (LYEL) insider trading

> In the 12 months to Nov 6, 2026, 2 LYEL insiders reported open-market sales of $74.5K across 3 filings; 4 insiders bought $75.0M.

Canonical: https://massive.com/quote/lyel/insider-trading
Latest filing: 2026-11-05 (last 12 months; source: SEC EDGAR)
Source: Massive (https://massive.com/docs/llms.txt)

## Summary

| Measure | Value | Detail |
| --- | --- | --- |
| Open-market sales | $74.5K | 3 filings · 2 insiders |
| Open-market purchases | $75.0M | 4 filings |
| Pre-arranged sales (10b5-1) | 2 of 3 | $274 of $74.5K sold (0%) |

## Open-market trades by insider

| Insider | Role | Sold | Bought | Filings | Pre-arranged (10b5-1) | Last filed |
| --- | --- | --- | --- | --- | --- | --- |
| ARCH Venture Fund IX Overage, L.P. | 10% owner | — | $25.0M | 1 | — | 2026-11-05 |
| Robert Nelsen | 10% owner | — | $25.0M | 1 | — | 2026-11-05 |
| ARCH Venture Fund IX, L.P. | 10% owner | — | $12.5M | 1 | — | 2026-03-09 |
| Kristina Burow | 10% owner | — | $12.5M | 1 | — | 2026-03-09 |
| Veronica Sanchez Bulis | VP, Corporate Controller | $74.2K | — | 1 | — | 2026-01-06 |
| Innovative Cellular Therapeutics Holdings Ltd | 10% owner | $274 | — | 2 | 100% of sales | 2026-07-20 |

## Open-market trades by filing

7 filings in the last 12 months, newest first.

| Filed | Traded | Insider | Role | Type | Shares | Avg price | Value | Held after | Filing |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 2026-11-05 | 2026-11-04 | Robert Nelsen | 10% owner | Purchase | 2,321,262 | $10.77 | $25.0M | 3,747,790 | — |
| 2026-11-05 | 2026-11-04 | ARCH Venture Fund IX Overage, L.P. | 10% owner | Purchase | 2,321,262 | $10.77 | $25.0M | 3,747,790 | — |
| 2026-07-20 | 2026-07-17 | Innovative Cellular Therapeutics Holdings Ltd | 10% owner | Sale (10b5-1) | 10 | $13.70 | $137 | 2,857,480 | — |
| 2026-07-17 | 2026-07-16 | Innovative Cellular Therapeutics Holdings Ltd | 10% owner | Sale (10b5-1) | 10 | $13.73 | $137 | 2,857,490 | — |
| 2026-03-09 | 2026-03-06 | Kristina Burow | 10% owner | Purchase | 488,090 | $25.61 | $12.5M | 1,426,528 | — |
| 2026-03-09 | 2026-03-06 | ARCH Venture Fund IX, L.P. | 10% owner | Purchase | 488,090 | $25.61 | $12.5M | 1,426,528 | — |
| 2026-01-06 | 2025-12-24 | Veronica Sanchez Bulis | VP, Corporate Controller | Sale | 2,072 | $35.80 | $74.2K | 7,141 | — |

## Other insider activity (not market trades)

- Tax withholding (sold to cover): 25 records
- Grants and awards: 4 records
- Other: 4 records

Reported on Form 4 but not purchases or sales in the market, so not counted in the totals above.

## How to read this page

- **Open-market purchase or sale**: A buy or sell of the company's stock at market price. Grants, option exercises, shares withheld for tax, gifts and employee stock plan purchases are listed separately and not counted.
- **Pre-arranged (10b5-1)**: The insider marked the filing as made under a trading plan set up in advance (SEC Rule 10b5-1). The mark covers the whole filing, and an unmarked filing may still be under a plan.
- **Filing date**: Insiders have two business days to report a trade. Totals and the chart use the filing date, when the trade became public.
- **Counted once**: When several owners (a fund and its partners, say) report the same trade, it's counted once. Corrected filings replace the originals.

## FAQ

### Has Lyell Immunopharma, Inc.'s CEO sold stock?

No. Lynn Seely (CEO) made no open-market sales filed as CEO in the last 12 months.

### How current is LYEL’s insider data?

These are LYEL Form 4 filings from the last year, refreshed daily. The Massive Form 4 API has the full, continuously updated record.

### What counts as an open-market buy or sell?

Only purchases and sales at the market price. Option exercises, grants, gifts, and shares withheld for taxes are reported on Form 4 but are left out of the buy and sell totals.

## Live data

This page joins two Massive endpoints: Form 4 filings and daily prices. The LYEL Form 4 request:

- `GET https://api.massive.com/stocks/filings/vX/form-4?tickers=LYEL&filing_date.gte=2025-11-06&sort=filing_date.desc&limit=500`

Requests need a Massive API key. API reference for agents: https://massive.com/docs/llms.txt. Connect an AI agent through the Massive MCP server: https://massive.com/docs/ai-tools.

## Related

- [Lyell Immunopharma, Inc. (LYEL) stock price](https://massive.com/quote/lyel.md)
- [Recent insider trading](https://massive.com/quote/insider-trading.md)
- [Markets overview](https://massive.com/quote/index.md)

Nothing here is investment advice. Data and content are provided for informational purposes under the Massive Terms of Service: https://massive.com/terms