Background: I'm a young 20-something, I won't be retiring for 40+ years, and the expense ratios for the funds offered in my company's 401(k) plan mostly suck. The company matches 35% of my contributions up to a limit. The plan doesn't offer a large cap fund.
I understand that one of the reasons an all-stock portfolio isn't recommended is because of the volatility, though stocks will provide some of the best long-term returns. Considering my scenario, what drawbacks would I have were I to solely invest in stock-based funds? (going by expense ratios, my only viable choices are Vanguard mid-cap at 0.24% and Vanguard small-cap at 0.30%)
This question appears to be related: If low-cost index funds are considered the best investment, why are there so many high-cost, managed funds?