Earlier quoted context omitted.
> you're not actually investing in capacity, the way you would be if you bought an IPO or even just a piece of equipment you could use to make something. while you are not directly investing in capacity like you might in an IPO, purchasing stock does create the same outcome. It's just not _you_ who is doing the capacity investing directly, but someone else who does so, as a result of the chain of investments.
It doesn't necessarily though. When I buy an IPO, my dollars go straight (kind of) into a company's bank account. When I buy stock on the market, my dollars go to whoever I bought the stock from, who will probably use those dollars to buy more stock. The only time a company ever receives dollars it can use is when it sells stock to the public or gets a loan, and the vast, vast majority of transactions on the stock ma…
If you could _only_ invest directly into capacity, the amount of dollars that people would be willing to put in would be much smaller than today's. That's because the risk profile is singular in direct capacity investment.
The reason the stock market can fund IPOs is because it allows the different stratas of risk to be separated, and taken on by different parties that want those risks. So without your dollar buying an existing stock, thus letting early investors for an IPO an exit, they would unlikely to want to invest in the IPO in the first place!