Here in the US, you can buy publicly traded companies in the US for a song; in fact, that was the source for the "acquiring" company in a lot of those reverse-acquisitions of the late 2000s / early 2010s: publicly traded companies that had a ticker, but were basically defunct. A company that wanted to go public without the scrutiny of an IPO process could "buy themselves" with the tiny, publicly traded company, thereby getting a ticker and access to retail investors. (This was not a good phenomenon, fwiw, though it definitely anticipated the SPAC craze... which was also not good, for similar reasons.)

If you list on a big exchange, your investors will expect revenue and profit to go brrr quarter after quarter forever. It's a treadmill you can never get off. Amazon is uniquely special in that Bezos persuaded investors to keep faith for the best part of a decade. Or perhaps "lucky": one wonders what their stock price would have done without the incredible luck of the former side hustle of AWS becoming the engine of their business. (Not to denigrate the incredible feat that it is, or the work that went into it.)

Regulation provides some practical limits on how small you can be, too. All those 10-Ks and audits and SOX compliance don't come cheap. You need to be big enough to employ specialists to do it or rich enough to partner up with Deloitte.

The alternative is to list on a pink sheet exchange, but then you are keeping company with a long long tail of companoes that give off sketchy vibes. A one man Nevada corporation selling healing oils, or an interest in a hitherto-undiscovered source of limitless energy. I cant think of any company that graduated from this part of the market into full DJI/Nasdaq respectability. Maybe someone knows of one?

Turns out mRNA stands for Moderna and I wish I put in more than 50 dollars as it went from ~$19 to almost ~$400 per share.