ATTO Insider Trading

Company officers and directors buying and selling their own stock, as reported to the SEC on Form 4.

55 open-market transactions — 9 purchases, 46 sales · 2026-08-05 to 2026-08-06

Date Ticker Insider Action Shares Price Filing
2026-08-06 ATTO Frazier Life Sciences XI, L.P. Buy 588.2K 17.00 SEC
2026-08-06 ATTO WALSH COLIN — Director Buy 500.0K 17.00 SEC
2026-08-06 ATTO GOLDMAN SACHS GROUP INC Buy 500.0K 17.00 SEC
2026-08-06 ATTO Redmile Group, LLC Buy 400.0K 17.00 SEC
2026-08-06 ATTO venBio Global Strategic Fund IV, L.P. Buy 382.4K 17.00 SEC
2026-08-06 ATTO Sanofi Buy 300.0K 17.00 SEC
2026-08-06 ATTO Redmile Group, LLC Buy 200.0K 17.00 SEC
2026-08-05 ATTO WALSH COLIN — Director Buy 85.0K 21.00 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Buy 85.0K 21.00 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 76.4K 21.04 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 76.4K 21.04 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 7.0K 22.03 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 7.0K 22.03 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 6.8K 21.61 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 6.8K 21.61 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 3.4K 22.02 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 3.4K 22.02 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 1.6K 22.06 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 1.6K 22.06 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 1.3K 22.03 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 1.3K 22.03 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 1.2K 22.19 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 1.2K 22.19 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 1.2K 21.84 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 1.2K 21.84 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 1.0K 22.05 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 1.0K 22.05 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 988 22.03 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 988 22.03 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 753 21.97 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 753 21.97 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 700 22.07 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 700 22.07 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 672 22.02 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 672 22.02 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 480 21.55 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 480 21.55 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 447 21.87 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 447 21.87 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 443 21.78 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 443 21.78 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 400 22.02 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 400 22.02 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 300 20.84 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 300 20.84 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 200 22.10 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 200 22.10 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 200 22.05 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 200 22.05 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 200 22.05 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 200 22.05 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 100 22.11 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 100 22.11 SEC
2026-08-05 ATTO WALSH COLIN — Director Sell 100 21.99 SEC
2026-08-05 ATTO GOLDMAN SACHS GROUP INC Sell 100 21.99 SEC

What Form 4 actually tells you

Officers, directors and anyone holding more than 10% of a company must report trades in its stock to the SEC within two business days, on Form 4. The filings are public the moment they land, and every row above links to the original.

Buys and sells are not symmetric

This is the thing worth internalising. An insider sells for a hundred reasons that say nothing about the company — diversification, a house, a tax bill, or a pre-scheduled 10b5-1 plan set up months earlier. An insider buying on the open market with their own money has exactly one obvious motive.

Which is why this page shows only open-market purchases and sales. Form 4 also reports option grants, option exercises and shares withheld to cover taxes; those are compensation mechanics, and screens that fold them in produce noise that looks like signal.

Timing and limits

Where this comes from

Parsed directly from SEC EDGAR — the daily filing index, then each Form 4's XML. Public domain, no vendor in between, which is why the original filing can be linked from every row.