Early this decade some investing pundits were predicting a new “roaring twenties.”

The one a century ago also started with a pandemic followed by a wave of innovation, risk-taking and enormous stock-market wealth. So far, so good.

Now another echo of that boom is giving exuberant investors enough rope to hang themselves: investments that can go to zero.

Of course any stock could do that, but you’d have to be truly reckless to lose every penny in a diversified portfolio. And when it comes to funds, mainly rich people allowed to invest in ones that occasionally go bust.

But a coming wave of leveraged products make that possible for the little guy by focusing on individual, usually volatile companies. We just got a preview from London.

Remember how shareholders of Advanced Micro Devices celebrated a week ago following its deal with OpenAI? Well it was awful news for owners of a GraniteShares exchange traded product that was three-times short the stock. Their announcement:

“As a result, and in accordance with the Terms and Conditions of the ETP, an Early Redemption Event has occurred. The Value per ETP Security has been determined as USD 0.0000.”

Four decimal places was a nice touch. GraniteShares recently filed to list similar U.S. products.

Funds that represent similarly leveraged returns on a basket of stocks have been available stateside for a while. For example, a triple inverse semiconductor index fund also fell sharply that day and is down by a whopping 99.99999% since inception. That still isn’t zero, and it took years.

When stocks crashed in 1929, many investors were ruined because they were allowed to buy on 10% margin—putting down a tenth of a stock’s price with the rest borrowed. And highflying funds from that era known as investment trusts had significant borrowings too, often buying other trusts that had their own borrowings. Owners were wiped out by what seemed like diversified funds.

Americans already lose lots of money with leveraged products these days because of decay and hidden costs. Basing them on more volatile individual stocks means more zeroes in investors’ future.

Other products are coming that frequently end in a goose egg: U.S. investors are getting access to perpetual futures for cryptocurrencies that could have as much as 100 times leverage. Friday’s bitcoin “perp” meltdown saw accounts wiped out and even winning traders picking up part of the tab.

But that’s crypto. Inserting the possibility of total loss into something that looks like a stock mutual fund at a time of maximum retail-investor excitement is taking the 1920s parallels to a new level.