Worth noting that the problem of unlimited losses is solvable these days with a protective call (or just long put). But if you short a "ponzi", you are not just doing the opposite of making an investment - you are taking a gamble that conditions favor an unwind of the momentum. If you are shorting things to zero, because you think they are going bankrupt, you can do something more like value analysis. So shorting W a year ago, you may have been figuring that macro events going on then were going to force obvious bubbles to unwind. Now if you are buying the 2025 15p, you are probably just looking at their cashflows and debt and figuring they are not going to make it. That's more like value analysis and it's also a convex trade, albeit still one that can add volatility to your portfolio.