Wednesday, October 28, 2026
Data from SEC filings, checked daily
Public filings, plainly told
WallStPal · PDF guide
MGNI Insider Trading: MAGNITE, INC. Insider Buys and Sells · https://wallstpal.com/stock/mgni/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

MAGNITE, INC. (MGNI) Insider Trading

17 open-market trades reported since Aug 18, 2026: 0 purchases worth $0 and 17 sales worth $5.95M.

By insider

InsiderRoleBuysBoughtSellsSoldLatest
Paul CaineDirector0$04$820KOct 14, 2026
Douglas S. KnopperDirector0$01$981KSep 18, 2026
Robert F. SpillaneDirector0$01$246KSep 16, 2026
David BuonaseraCTO0$03$180KSep 16, 2026
Aaron SaltzGeneral Counsel0$01$936KSep 11, 2026
Katie Seitz EvansSee Remarks0$03$1.36MSep 11, 2026
Sarah Patricia HardenDirector0$02$1.15MAug 28, 2026
Sean Patrick BuckleySee Remarks0$02$270KAug 18, 2026

All trades

MGNI insider trades
FiledTradedInsiderRoleTypeSharesPrice ($)ValueHolding3 mo. afterFiling
Oct 14Oct 12Paul CaineDirectorDirector▼ SELL10b5-112,50025.29$316K−9.1%Form 4 ↗
Sep 18Sep 17Douglas S. KnopperDirectorDirector▼ SELL10b5-137,33726.28$981K−42%Form 4 ↗
Sep 18Sep 17Paul CaineDirectorDirector▼ SELL10b5-17,50026.50$199K−5.2%Form 4 ↗
Sep 16Sep 14Robert F. SpillaneDirectorDirector▼ SELL10,36323.76$246K−15%Form 4 ↗
Sep 16Sep 14David BuonaseraCTOCTO▼ SELL10b5-11,16524.00$28K−0.5%Form 4 ↗
Sep 11Sep 10Aaron SaltzGeneral CounselGeneral Counsel▼ SELL10b5-140,00023.41$936K−15%Form 4 ↗
Sep 11Sep 11Katie Seitz EvansSee RemarksSee Remarks▼ SELL10b5-113,99724.00$336K−3.1%Form 4 ↗
Sep 11Sep 10Paul CaineDirectorDirector▼ SELL10b5-15,00023.53$118K−3.3%Form 4 ↗
Sep 10Sep 8Katie Seitz EvansSee RemarksSee Remarks▼ SELL10b5-132,28523.63$763K−6.5%Form 4 ↗
Sep 10Sep 9Katie Seitz EvansSee RemarksSee Remarks▼ SELL10b5-111,10023.46$260K−2.4%Form 4 ↗
Sep 3Sep 1David BuonaseraCTOCTO▼ SELL10b5-15,37123.42$126K−2.1%Form 4 ↗
Sep 3Sep 2David BuonaseraCTOCTO▼ SELL10b5-11,04325.00$26K−0.4%Form 4 ↗
Aug 28Aug 26Sarah Patricia HardenDirectorDirector▼ SELL10b5-130,55023.31$712K−19%Form 4 ↗
Aug 28Aug 28Sarah Patricia HardenDirectorDirector▼ SELL10b5-118,43624.00$442K−14%Form 4 ↗
Aug 18Aug 17Sean Patrick BuckleySee RemarksSee Remarks▼ SELL10b5-18,27124.31$201K−2.7%Form 4 ↗
Aug 18Aug 14Paul CaineDirectorDirector▼ SELL10b5-17,50025.00$188K−4.8%Form 4 ↗
Aug 18Aug 18Sean Patrick BuckleySee RemarksSee Remarks▼ SELL10b5-12,75925.00$69K−0.9%Form 4 ↗
Source: SEC Form 4 filings, retrieved Oct 28, 2026. How we read filings