David Nierenberg has bought stock on 18 days since Jun 2016

David Nierenberg is a professional investor and corporate insider who serves as president of Nierenberg Investment Management Company, Inc., an investment firm that manages concentrated positions in a number of public companies.( He is a long‑time significant shareholder in Potbelly Corp (NASDAQ: PBPB), where he is disclosed as a 10% owner in SEC filings and related ownership summaries.( As of early 2025, Nierenberg and affiliated entities held over 3 million Potbelly shares, and he has executed multiple open‑market purchases in recent months, including transactions reported in December 2024 and January 2025.( His Form 13D filing for Potbelly identifies him personally and lists him as president and signatory, underscoring his role as an individual investor leading his firm’s engagement with the company.(

Beyond Potbelly, Nierenberg is a notable large shareholder and insider at several other U.S. public companies, including Amedisys Inc., Natus Medical Inc., Rosetta Stone Inc., Flotek Industries Inc., and Houston Wire & Cable Co., where he has held roles such as director and 10% owner.( GuruFocus and SEC ownership data estimate his net worth at over $200 million, reflecting substantial stakes across a portfolio of nine reporting companies.( In the investment community he is tracked as a value‑oriented manager ("Trades, Portfolio") whose strategic acquisitions, such as his ongoing Potbelly stake increases, are followed by market observers for insight into his views on company fundamentals.(

Written by Perplexity from public sources.