Christmas music has already begun in some stores, which also means that it’s time to begin end-of-year planning. For many, this means looking at your 401(k), and so I thought I’d share some news and tips from a recent article. Brightscope Inc., a retirement plan rating company, recently compiled a list of the 10 most commonly held mutual funds in 401(k)s. Generally, it hasn’t been a bad year for 401(k)s and investors. Nevertheless, many of the top ten underperformed the Standard and Poor’s 500 stock index. This may simply be a sign that size is not always conducive to…