You don’t want to overdo it, but it’s important to stay on top of things. Generally speaking, if your portfolio is run by professional investment managers, you should check the performance quarterly; otherwise, you may not give them enough room to do their jobs.

If you run your own portfolio, it is entirely up to you how often you check the performance, but be aware that the closer and more short-term your focus gets, the higher the chance you have of losing sight of the bigger picture.

It is often hard for individuals to remove emotional bias from their investment decisions, but forums and articles such as those found here can help an individual remain objective in his or her decision-making.

Is there a Benefit to Self-Managing?
Should I Pay for Financial Planning Services?
What Should I Compare the Performance of My Portfolio With?