The following commentary comes from an independent investor or market observer as part of TheStreet's guest contributor program, which is separate from the company's news coverage.NEW YORK ( Insider Monkey) -- Corporate insiders have material non-public information about their companies. Trading on such information is illegal and some insiders were investigated and caught, but there are still other insiders trading in the gray area. Even when insiders do not act directly on material non-public information, they are still able to benefit from it. They can delay their purchases when they know negative news is going to be released, and vice versa. Sometimes insiders do not have material non-public information, but they still have an edge over ordinary investors: they know their companies and their industries way better than ordinary investors. That's why we have been encouraging investors to focus on the investments of insiders. Below we compiled a list of industrial goods stocks insiders are bullish about. All companies have at least $10 billion market cap and were purchased by at least one insider during the past three months. The market data is sourced from Finviz.