Utilize your financial knowledge, give your answer or opinion to the input question or subject . Answer format is not limited.

When should you use an actively managed mutual fund in a 401k?
For US stocks it's a bit of a gamble. Many actively managed funds underperform the market indexes, but some of them outperform in many years. With an index you will get average results. With an active manager you "might" do better than average. So you can view active management as a higher risk, potentially higher reward investment approach. On the other hand, if you want to diversify some of your investments into international stocks, bonds, junk bonds, and real estate (REITs) active management is highly likely to be better than indexing. For these specialized areas specialized knowledge and research is needed.