With this much uncertainty, paying ~$2000 for 1 bitcoin seems insane to me. But that's why I don't invest in cryptocurrencies; too much volatility for my taste.
The difference is that when I buy a stock, they have a balance sheet, usually physical and/or digital assets like buildings, datacenters, warehouses, trucks, intellectual property, software programs, patents. They usually also have people, and some type of plan to leverage everything so that the sum is greater then the parts. That's an investment, when you pay them to leverage their assets and people.
Even in a situation like yahoo, because there are real assets, even though they didn't leverage on the dream, the were still parted and sold for scrap because there was real value behind the stock. That won't happen with BTC.
Gold is a commodity of a specific know content, it doesn't need a balance sheet. The only thing left is to set the price, which you can speculate on. But is does have physical value at some price floor and you're just speculating on the demand. Basically the same for any commodity, oil, wheat, orange juice.
Just like the the USD is not a commodity, neither is BTC, so that's a bit disingenuous to compare it to gold, or a publicly traded and regulated stock. It's not even close.
edit: autocorrect.