If you're holding equities or any other assets that you can easily liquidate then there's really no functional difference between "losing" $50,000 in stock value or "losing" $50,000 in hard cash, regardless of whether you sell those stocks or not. Theoretically the stock valuation could go back up, but that's just as true as an equivalent amount of cash that you could invest in the market at those lower valuations.
If you're holding equities or any other assets that you can easily liquidate then there's really no functional difference between "losing" $50,000 in stock value or "losing" $50,000 in hard cash, regardless of whether you sell those stocks or not. Theoretically the stock valuation could go back up, but that's just as true as an equivalent amount of cash that you could invest in the market at those lower valuations.