When Fred Penney, an engineer in Grand Falls-Windsor, Nfld., started his investing blog three years ago, his main goal was to become a better investor. “I wanted the blog to serve as a trading diary,” he says. “A number of great traders have stated that they found it very helpful to maintain a trading log and to review it to learn from both the good and the bad trades.”

Penney figures that blogging about his trend trading strategy is better than documenting his moves for his own reference. “I am a much better investor because of it,” he says. “I’m continuously challenging myself to improve my investing strategy.” He finds that visitors to his blog, ETF2X.com, can act as a sounding board for his decisions and point out mistakes that he hadn’t thought of.

“Writing up your ideas is an excellent way to find out what you know and don’t know,” says Chris Robinson, associate professor of finance at York University. But he warns that relying on comments to critique your strategies is a gamble. “Someone who relies on chance comments from an unknown source as a quality check is getting what he or she is paying for.”

Ram Balakrishnan, author of the Canadian Capitalist blog on MoneySense.ca, agrees. He says the best thing about blogging is that it’s great for self-reflection. For instance, he says looking back at his “laughably ridiculous” posts about his favourite stock picks in the early days of his blog helped convince him to switch to index investing.

However, he says not all of the commentary he gets from the public is useful. Rather than following every morsel of advice he gets, Balakrishnan uses the general tenor of the comments to gauge investor sentiment. “It gives me an idea of what people are most interested in at the moment,” he says. “And typically, if a lot of investors are piling into something, it’s not a good place to be.”