Insiders at regional banks can’t help but notice the steep declines for their stocks over the past two months, and several stepped in over the past week to buy the dip. Several regional banks saw insiders buy shares over the past seven days, according to VerityData. Three of those came from Zions Bancorp , whose shares are down nearly 60% this year. Insider buying is tracked by some professional investors as a potential sign of company quality. The theory is that buying by corporate executives and boards members suggest that the insiders are confident in the firm and think the stock is underpriced. Here are the five U.S. companies with the biggest insider buying over the past week, according to VerityData. Zions Bancorp — Multiple executives combined to buy more than $2 million worth of shares in recent days, with Zions President and COO Scott McLean leading the way with a buy of about $1 million on April 28. Impinj — Chairman Steve Sanghi bought nearly $2 million of the tech stock on May 1. Lakeland Financial — Two directors combined to scoop up just over $1 million worth of the regional bank stock on April 28. US Bancorp — Director Scott Wine made his first insider transaction on record at US Bancorp with a buy of about $1 million on April 28. Wolfspeed — The CEO and a director of the semiconductor company combined to buy about $753,000 of Wolfspeed shares on April 28. In addition Zions, two other banks that saw insider buying were Lakeland Financial and US Bancorp. Lakeland now has a market cap of under $2 billion, while US Bancorp is much bigger out more than $44 billion. Outside of the banks, tech company Impinj had the largest buy — about $2 million from Chairman Steve Sanghi. However, Impinj’s chief revenue officer made a 10b5-1 sale on the same day that would of roughly the same size as Sanghi’s purchase, according to Verity. That stock is down about 21% year to date. Buying the dip was a theme of all of the top five insider buying companies. Wolfspeed, a chip company where two insiders made buys last week, is down more than 40% for the year. See more about Insider Buying on CNBC’s ” Last Call ,” weekdays at 7 p.m. ET.