or maybe a collapse of the economy, or perhaps the dollar collapses and is replaced by some other currency? 

Don't pick something that's super high risk, high-return (crypto, for ex). there's not enough learning potential from that IMO and you don't have enough context to be making the investment on an informed basis.

Stock, crypto, and other investors pretty much universally agree that's it not wise to buy when prices are at a peak. 

I have gotten requests twice today from Dave Myer @datadeli with one letter off wanting me to invest in crypto.

Options are the stock market, crypto, precious metals, real estate, businesses, or stay in cash etc...   

Shock number #2: His alternative bucket was 13% of his total and had stuff in there I had never heard of, including MLP’s and Life Settlements along with a much larger stake in cryptocurrency than I would have imagined and made me wonder if my portfolio could use some out of the box thinking on some of that.

I still think real estate is one of the best asset classes to invest in today compared to other assets such as stock or crypto.

I think your chances or being audited are slim - unless you are also buying and selling cryptocurrency and not disclosing this.Consult with a CPA or an EA for the specifics in your case. 

It was cited today in the WSJ with respect to cryptocurrency holdings. 

My credit is **** due to losing 1.7 m in Crypto winter 2018, but I'm a serial entrepreneur and can run this business with my eyes closed.