Back in the day, the answer would have been bearer bonds, but they're no longer popular instruments.
The financial instrument of choice for movie heist villains from the 1970s to early 2000s.
https://en.wikipedia.org/wiki/Chiasso_financial_smuggling_ca...
> The total value of the counterfeit bonds was estimated at approximately one percent of total U.S. GDP in 2008
> The Financial Times also reported that the two suspects "had been released" by Italian authorities.
I guess they helped direct the police to the actual counterfeiters.
> An earlier billion-dollar bond case was recorded in 2002, when the United States Court of Appeals for the Seventh Circuit, located in Chicago, heard a case from two men who sought $100 billion from the Federal Reserve Bank of Chicago.
So two guys tried to bring a fake bearer bond worth $100B and tried to cash it out? That's hilarious. It also sounds like they didn't even get in trouble.
Some choice excerpts:
> ... Japanese nationals in their 50s ... who had attempted to enter Switzerland with a suitcase ... containing what ... appeared to be U.S. Treasury Bonds worth $134.5 billion.
Enough to buy a couple of Twitters!
> The Financial Times also reported that the two suspects "had been released" by Italian authorities.
??????????????????????
edit:
> On September 18, 2009, a similar incident was reported ... by the Italian financial military police ... involving two Philippines nationals smuggling purported U.S. Treasury bonds valued at approximately $180 billion
Why do these involve Asian nationals? I'm just not a good enough crook to determine the advantage here...
> On February 17, 2012, it was reported that Italian police had seized $6 trillion in counterfeit U.S. bonds....
If you're gonna commit a crime, you might as well swing for the fences, eh?
This is Dr. Evil type stuff!
Kansas City shuffle. You find someone who wants to help run the con, but they're actually the mark.
At least investment/corporate bonds usually expire, so the bearer ones eventually wash out.
If another resident of Zhong's household had discarded the popcorn tin, he could have been out $1B. It's is difficult, but not impossible (see fat-finger transactions) to do that with other asset classes.
Impossible to prove he didn’t have his private keys backed up elsewhere.
(I understand these hardware wallets let you load up as many as you want.)
It's interesting how the defendant tried to hide his bitcoin holdings in very low-tech ways.
The utility ease of holding bitcoin is apparent with this seizure. What other asset could you hide the equivalent of $1B USD in a floor safe and a popcorn tin and without having to use a 3rd party custodian?