Hoping someone can offer some help. I'm helping my mother with her investments and one of her stock holdings was purchased by another company. I typically look up her holdings quarterly but this holding suddenly disappeared (couldn't find any info for end of September). My mother recently received a letter from APA (an unclaimed property company) saying we needed to file a form with a medallion certificate to recover the stock and that APA keeps 25% of the holdings value as a fee. My mother never received any notice about the company being sold (the APA letter was our first notice) since I hold her mail at a PO Box.