How Much Should I Invest in Non-Liquid Investments?

Investment liquidity is doubtlessly a good thing. Yet, that doesn't mean that illiquidity is doubtlessly a bad thing. In fact, liquidity can sometimes be a curse and illiquidity can sometimes be a blessing. This is the realization felt by traders after they've participated in a panic (incidentally, it's easy to label a panic in hindsight, but very difficult to see a situation as temporary, emotional selling while it's happening and when your net worth is falling!).