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Nierenberg Investment Management Company, LLC

CIK 1282683 · last filed 2026-07-24

Nierenberg Investment Management Company, LLC is a corporate insider who has filed 64 SEC Form 4 insider transactions across 8 companies since 2007. The most recent filing shows the insider sold $79.0K of RVSB on Jul 24, 2026. Across all open-market trades the lifetime net is +$196.1M, making them a net buyer over the disclosed history. Current disclosed insider exposure totals $761.1K 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

$761.1K

Companies

8

Total Filings

64

Lifetime Open-Market Net

$196.08M

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
RVSB 10%+ Owner 79,388 $5.37 $426.3K -$79.0K 1 2026-07-24
POTBELLY CORP (PBPB) Delisted 10%+ Owner 127,317 $17.12 $2.18M $1.62M 4 2025-03-31
ELECTRO SCIENTIFIC INDUSTRIES INC (ESIO) Delisted Director 559,683 — — $16.05M 18 2015-01-30
ASSET ACCEPTANCE CAPITAL CORP (AACC) Delisted 10%+ Owner 645,234 — — $45.38M 10 2013-04-19
MOVE 10%+ Owner 30,079 $11.13 $334.8K $79.88M 6 2012-11-06
MEDCATH CORP (MDTH) Delisted 10%+ Owner 473,596 — — $20.82M 7 2011-06-02
NATUS MEDICAL INC (BABY) Delisted 10%+ Owner 129,931 — — $32.08M 5 2010-02-24
Azenta, Inc. (BRKS) Delisted 10%+ Owner 0 $113.10 $0 $329.4K 2 2008-07-25

Recent Filings

64 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
2026-07-24 RVSB Sell (S) −15,000 -$79.0K EDGAR
2025-03-31 POTBELLY CORP (PBPB) Delisted Buy (P) +44,338 $415.0K EDGAR
2025-01-10 POTBELLY CORP (PBPB) Delisted Buy (P) +15,200 $140.3K EDGAR
2024-12-20 POTBELLY CORP (PBPB) Delisted Buy (P) +9,480 $88.7K EDGAR
2024-08-07 POTBELLY CORP (PBPB) Delisted Buy (P) +148,690 $971.2K EDGAR
2015-01-30 ELECTRO SCIENTIFIC INDUSTRIES INC (ESIO) Delisted Other (J) −1,265,420 $0 EDGAR
2014-11-12 — Sell (S) −3,204,704 -$7.85M
2014-01-03 — Exer (M) +7,500 $0
2013-12-05 ELECTRO SCIENTIFIC INDUSTRIES INC (ESIO) Delisted Grant (A) +95 $0 EDGAR
2013-09-06 — Grant (A) — $0
Showing 1–10 of 64
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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.