WILLIAM P SCULLY

CIK 1045463 · last filed 2026-08-10

WILLIAM P SCULLY is a corporate insider who has filed 19 SEC Form 4 insider transactions across 2 companies since 2014. The most recent filing shows the insider bought $323.2K of PRTA on Aug 10, 2026. Across all open-market trades the lifetime net is +$6.8M, making them a net buyer over the disclosed history. Current disclosed insider exposure totals $7.8M 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.

Disclosed Exposure

$7.76M

Companies

2

Total Filings

19

Lifetime Open-Market Net

$6.76M

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
PRTA	10%+ Owner	842,000	$9.22	$7.76M	$6.17M	8	2026-08-10
YIELD10 BIOSCIENCE, INC. (MBLX) Delisted	10%+ Owner	2,933,333	—	—	$591.1K	11	2016-09-14

Recent Filings

19 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
2026-08-10	PRTA	Buy (P)	+37,500	$323.2K	EDGAR
2026-06-18	PRTA	Buy (P)	+20,000	$158.0K	EDGAR
2026-06-16	PRTA	Gift (G)	−325,000	$0	EDGAR
2026-06-12	PRTA	Buy (P)	+125,000	$1.02M	EDGAR
2026-06-05	PRTA	Buy (P)	+50,000	$465.3K	EDGAR
2026-06-03	PRTA	Buy (P)	+50,000	$471.3K	EDGAR
2026-05-26	PRTA	Buy (P)	+100,000	$981.3K	EDGAR
2025-05-02	PRTA	Mixed	−110,264	$2.75M	EDGAR
2016-09-14	YIELD10 BIOSCIENCE, INC. (MBLX) Delisted	Sell (S)	−68,333	-$22.5K	EDGAR
2016-09-12	YIELD10 BIOSCIENCE, INC. (MBLX) Delisted	Sell (S)	−165,000	-$57.4K	EDGAR

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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.