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MICHAEL OREILLY

CIK 1192729 · Vice Chairman · last filed 2026-06-17

MICHAEL OREILLY is a Vice Chairman who has filed 52 SEC Form 4 insider transactions across 3 companies since 2007. The most recent filing, for MKL, was dated Jun 17, 2026. Across all open-market trades the lifetime net is −$13.1M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $98.5M across reported positions.

"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.

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Disclosed Exposure

$98.47M

Companies

3

Total Filings

52

Lifetime Open-Market Net

-$13.12M

Holdings By Company

Latest on-record share count from this person's most recent non-derivative Form 4 transaction in each company. Disclosed exposure = shares × current underlying price.
Symbol Role Shares Price Disclosed Exposure Lifetime OM Net Filings Latest Filed
MKL Director 3,934 $2039.68 $8.03M $0 25 2026-06-17
ALTERRA CAPITAL HOLDINGS Ltd (ALTE) Delisted Director 24,000 — — $189.8K 4 2012-05-09
CB Vice Chairman 248,999 $363.23 $90.44M -$13.31M 22 2008-05-07

Recent Filings

52 filings
Insider activity across all companies, newest first. Form 4 rows are post-trade confirmations (buys, sells, grants, exercises). Notice (144) rows are pre-trade notices of intent to sell restricted or control stock under Rule 144 — they may not all execute. Compare adjacent dates to see which notices became actual sales.
Filed Symbol Action Net Shares Net $ Link
2026-06-17 MKL Other (J) +89 $150.0K EDGAR
2026-05-22 MKL Grant (A) +89 $0 EDGAR
2025-06-17 MKL Other (J) +80 $140.0K EDGAR
2025-05-23 MKL Grant (A) +88 $0 EDGAR
2024-06-17 MKL Other (J) +100 $140.0K EDGAR
2024-05-23 MKL Grant (A) +100 $0 EDGAR
2023-06-16 MKL Other (J) +116 $140.0K EDGAR
2023-05-18 MKL Grant (A) +122 $0 EDGAR
2022-05-16 MKL Other (J) +117 $140.0K EDGAR
2022-05-13 MKL Grant (A) +129 $0 EDGAR
Showing 1–10 of 52
Page 1 of 6
Form 4 codes: P = open-market purchase · S = open-market sale · A = grant/award · M = option exercise · F = tax withholding at vest · G = bona-fide gift · D = disposition to issuer · J = other (see filing footnote). Only P / S codes carry directional signal.
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.