PETER Y CHUNG

CIK 1239366 · last filed 2026-05-18

"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

$7.52M

Companies

8

Total Filings

75

Lifetime Open-Market Net

-$1.62B

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
MTSI Director 6,781 $228.71 $1.55M -$395.70M 27 2026-05-18
ATEN Director 207,298 $28.78 $5.97M -$88.78M 19 2026-04-24
Acacia Communications, Inc. (ACIA) Delisted Director 14,600 -$164.15M 7 2019-05-17
Casa Systems Inc (CASA) Delisted Director 34,124,480 $0.04 $1.19M -$235.88M 1 2018-04-30
Ubiquiti Inc. (UBNT) Delisted Director 4,822,815 -$738.25M 10 2013-09-16
NightHawk Radiology Holdings Inc (NHWK) Delisted Director 0 $0.41 $0 $0 7 2010-12-23
SeaBright Holdings, Inc. (SBX) Delisted Director 23,096 $0 1 2009-05-21
SeaBright Holdings, Inc. (SEAB) Delisted Director 18,611 $0 1 2008-05-22

Recent Filings · Page 3 of 8

75 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
2021-03-11 MTSI Grant (A) +2,093 $0 EDGAR
2021-03-03 Disp (D) −14,600 -$1.68M
2020-11-13 MTSI Mixed +850,311 $11 EDGAR
2020-05-28 ATEN Grant (A) +21,865 $0 EDGAR
2020-03-10 MTSI Grant (A) +5,414 $0 EDGAR
2019-12-06 ATEN Grant (A) +23,547 $0 EDGAR
2019-05-17 Acacia Communications, Inc. (ACIA) Delisted Grant (A) +4,010 $0 EDGAR
2019-03-05 MTSI Grant (A) +6,656 $0 EDGAR
2019-02-28 Acacia Communications, Inc. (ACIA) Delisted Sell (S) −1,300,127 -$67.93M EDGAR
2018-11-09 ATEN Grant (A) +23,112 $0 EDGAR
Showing 2130 of 75
Page 3 of 8
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.