InsiderTrades

Form 4 for AMG AFFILIATED MANAGERS GROUP, INC.

Accepted 2026-03-09 00:00:00 ET · period of report 2026-03-05 · accession 0001004434-26-000023 · SEC index · Original document

Summary rows

Aggregated the way they appear in lists: one row per insider, transaction code and security table.

X Filed Traded Ticker Insider Title Type Price Qty Owned ΔOwn Value
D 2026-03-09 2026-03-05 AMG STARR LOREN M Dir M - OptEx $0.00 +652 1,937 +51% $0
D 2026-03-09 2026-03-05 AMG STARR LOREN M Dir M - OptEx $0.00 -652 2,362 -22% $0
DM 2026-03-09 2026-03-05 AMG STARR LOREN M Dir A - Grant $0.00 +760 503 New $0

Purchase Sale Sale after option exercise All abbreviations

Every reported transaction

#TableSecurityDateCodeA/DSharesPriceOwned afterOwnExercise / expiryUnderlyingFootnotes
1 Common Common Stock 2026-03-05 M A 652 $0.00 1,937 D — — (F1) Reflects the vesting of previously reported awards. Awards vest 2025-2028.
2 Derivative Stock Units 2026-03-05 M D 652 $0.00 2,362 D — · — to — 652 Common Stock (F2) Inclusive of previously reported deferred stock units. (F1) Reflects the vesting of previously reported awards. Awards vest 2025-2028.
3 Derivative Deferred Stock Units 2026-03-05 A A 257 $0.00 257 D — · — to — 257 Common Stock (F4) Reflects cash fees that the director has elected to defer under the Company's deferred compensation plan, which are notionally invested in a measurement fund tracking the Company's common stock during the deferral period. Each deferred stock unit is equal to one share of the Company's common stock, and becomes distributable in common stock upon the reporting person's separation from service as a member of the Board of Directors of the Company.
4 Derivative Stock Units 2026-03-05 A A 503 $0.00 503 D — · — to — 503 Common Stock (F3) Each stock unit represents a right to receive one share of the Company's common stock upon vesting. The stock units vest in full on March 5, 2027.