Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

How to convince someone they're too risk averse or conservative with investments?
(Leaving aside the question of why should you try and convince him...) I don't know about a very convincing "tl;dr" online resource, but two books in particular convinced me that active management is generally foolish, but staying out of the markets is also foolish.  They are: The Intelligent Asset Allocator: How to Build Your Portfolio to Maximize Returns and Minimize Risk by William Bernstein, and A Random Walk Down Wall Street: The Time Tested-Strategy for Successful Investing by Burton G. Malkiel Berstein's book really drives home the fact that adding some amount of a risky asset class to a portfolio can actually reduce overall portfolio risk. Some folks won a Nobel Prize for coming up with this modern portfolio theory stuff. If your friend is truly risk-averse, he can't afford not to diversify.  The single asset class he's focusing on certainly has risks, most likely inflation / purchasing power risk ... and that risk that could be reduced by including some percentage of other assets to compensate, even small amounts. Perhaps the issue is one of psychology? Many people can't stomach the ups-and-downs of the stock market.  Bernstein's also-excellent follow-up book, The Four Pillars of Investing: Lessons for Building a Winning Portfolio, specifically addresses psychology as one of the pillars.