Several executives committed their own, personal money to buying their company’s stock this week. Many professional investors track corporate executives own buying and selling of stock as a signal of confidence in a company’s business outlook. The idea is that individuals at a company’s executive or board level who are willing to put their own money into the shares may see the stock as undervalued. CNBC Pro screened for the five U.S. companies with the biggest insider buying activity over the past week, using data from VerityData. The data includes companies with market caps of at least $1 billion. It excludes funds that are listed as directors. Here are the top insider buys: Air Products & Chemicals — CEO Seifi Ghasemi bought 11,000 shares on Monday at an average price of $264.42 for a total purchase of $2.91 million. Intel — Director Lip-Bu Tan purchased 66,000 shares at an average price of $37.84 for a total of $2.5 million. Neumora Therapeutics — Director Kristina Burow purchased some 175,000 shares in multiple tranches between Nov. 8 and Nov. 14, at an average price of $11.14 for a total of $1.96 million. Opko Health — CEO Phillip Frost bought 1 million shares at $1.27 apiece in a “high IQ” buy for a total of $1.27 million. Mercury Systems — Director Orlando Carvalho added 35,000 shares at an average price of $33.83 for a total of nearly $1.18 million, more than doubling his holdings. For Air Products’ Ghasemi the purchase was his second in two weeks. On Nov. 8, he purchased another 10,000 shares. Opko CEO Frost bought the dip in his company stock, which was down about 30% in the prior three months. His shares are held indirectly via trusts, according to a filing. Last week, Opko reported its latest quarterly financial results, including earnings that were in line with expectations and a revenue miss, according to FactSet. However, expectations for the quarter and year ahead were in the middle of analysts expectations. Mercury Systems’ Carvalho bought his shares about a week after the company reported a quarterly loss in its fiscal first quarter, while FactSet had projected earnings of 18 cents per share. It missed big on revenue too, posting $181 million versus an average analyst estimate of $218.5 million. Another notable insider purchase this week came from SolarEdge Technologies ‘ director Avery Moore, who bought about 15,000 shares at an average price of $70.96 for a total of $1.09 million. Shares of the company plunged 60% over the last three months. SolarEdge reported a quarterly loss at the start of this month and weaker-than-expected revenue.