Anyone with cash and low-leverage cash producing assets.

And it will be a challenge deciding who really has cash and what cash really means when the bubble will burst.

I remember that for a short but intense period of time money-market funds were in negative territory in late October 2008, which was really interesting because they were seen as basically cash (rightly or wrongly, that’s another discussion) and a run on them would have made many people very, very unhappy.

This is a pretty good answer. With cash you are total contrarian in the current environment. But this strategy also comes with risk. "Haircut" etc.

"Assets? Physical, material goods? Or investment vehicles like bonds and funds?"

Everything.

"What happens when the bubble bursts?"

Good question. High inflation? Strong recession? Or decades of stagflation? Everything is possible. The future is hard to predict.

"What doesn't lose value? Who doesn't wind up underwater?"

"No place left to hide".

Gold

Wow, downvotes. The hate for gold is strong, never really understood why.

The fact is that gold is one of the few asset classes that are safe.

Gold has the volatility of the stock market, with lower returns than bonds: https://www.portfoliovisualizer.com/backtest-asset-class-all...

I wouldn't be so sure, it is only worth much because we believe so. (Likewise platinum.) They will bubble and crash.

As opposed to say steel and copper which are tied to industrial supply and demand.

Money is shared fiction too. The difference is we can print an infinite supply of it but only have a finite supply of gold in the world.