Insider investing is a great tool. It can cut through a lot of the market noise, and get down to the brass tacks of investing: Where can a profit be made?

After all, corporate insiders, like a CEO, CFO, and others, have a lot of knowledge about a company, far more than what’s disclosed in quarterly earnings reports. When they buy their own shares, it’s for one reason only: Shares are undervalued and likely to move higher.

Of course, the market may take time to catch up to the opinion of these insiders. That’s why astute insiders keep adding to their stake as the market remains out of favor. We’ve found three companies where insiders have been coming back time and again in the past year to buy shares.