The early days of November have seen several major stock purchases by corporate insiders, according to securities filings and Verity Data. Insider buying is closely watched by professional investors, as it can be a sign that those closest to the company are more bullish on its prospects than the stock market. With earnings season winding down and most stocks still sharply lower for the year, this is a window for insiders to deliver a vote of confidence in their company. The biggest name on the list is Boeing CEO Dave Calhoun, who bought 25,000 shares for roughly $4 million. That is the biggest insider buy at Boeing in 19 years, according to Verity. Shares of Boeing are down nearly 12% year to date. However, Calhoun's purchase is not close to being the biggest recent purchase. Here are the top five recent insider buys, according to Verity: 1. Charter Communications : Director Eric Louis Zinterhofer bought $10.2 million worth of stock on Nov. 1. 2. CME Group : $8.26 million buy from director William Shepard, the biggest on record for CME Group. 3. Boeing: Calhoun buys about $4 million worth of stock 4. National Storage Affiliates Trust : Executive chairman Arlen Dale Nordhagen bought about $2 million worth of shares on Nov. 4, with several other executives making smaller buys around the same time. The move partially reverses a sale Nordhagen made in March. 5. Caesar's Entertainment : Michael Pegram bought 25,000 shares for about $1.1 million on Nov. 4. The big purchase at Charter comes as the cable company's stock is down more than 40% year to date. The owner of Spectrum Internet has seen consistent selling this year from partner companies, including Liberty Broadband, that own a large stake in Charter. Those sales were significantly bigger than Zinterhofer's purchase. The buy at CME Group from William Shepard looks relatively more substantial. While CME Group has seen selling from several directors this year, Shepard's purchase of more than 48,000 shares means that insider buys now outnumber sales in 2022. The stock is down about 24% year to date.