Insider buying and selling can occasionally tip the scales on a stock, James Cramer said on his "RealMoney" radio show. For example, Cramer is "itching to take action" in Lions Gate Entertainment ( LGF) because of strong fundamentals coupled with insider buying. Lions Gate insiders have recently made "concentrated open market" purchases, and such insider buying is an example of something that catches Cramer's eye and prompts him to dig deeper. On the other hand, Overstock.com ( OSTK), while it has lots of insider buying, is a "battleground" that Cramer does not want to get caught up in. He also doesn't like the business model, he said. Finally, Pentair ( PNR) is an example where an insider sale tipped the scale toward selling, said Cramer. On Wednesday, Cramer sold his position in Pentair after the CEO filed Tuesday to sell 30,000 shares. Some had speculated on Pentair as a hurricane rebuild play. However, with the stock near its 52-week low, less-than-stellar fundamentals and the CEO selling stock, there must not be any big orders coming, said Cramer. "If there were, this guy should know," he said. A caller asked about Comstock Homebuilding ( CHCI). Cramer said the company is being squeezed by rising raw costs, and the latest Fed beige book report indicates housing has "cooled a little bit." That information coupled with the devastation from Hurricane Katrina could cause the Fed to stop raising rates, said Cramer. The bottom line for Cramer is "at eight times earnings, it's not worth selling." Cramer would hold the stock. Another caller asked about Ultra Petroleum ( UPL). Cramer was a fan of the stock. He "thinks it goes higher." But he recommended selling a little if you have a big gain. Cramer said Spectranetics ( SPNC) was "not a bad company." He said the stock seemed stretched, though, so he would "take a little off the table and let the rest run."