After a startup has grown larger (hopefully $100 million in revenue), a good way for founders and early investors to exit is via a listing on a stock exchange of the company. The overall leaders in this aspect is the Nasdaq and New York Stock Exchange, who really are the only western stock exchanges for very large companies ($10 billion+ in market capitalization) to list.
But for smaller companies there are many local/national stock exchanges to list at, and the Stockholm Stock Exchange and the affiliated First North are two good places for this.
One interesting aspect is when a company is not doing great and gets an acquisition offer to sell all shares and leave the stock exchange. One such example in Stockholm is Readly, a digital magazine service. The company listed in 2021 and have had a tough time growing (ca 30 % growth and significant losses planned for another 1-2 years). Local major publisher Bonnier offered to buy out Readly (as they would likely get economies of scope and a better licensing situation as they are a major magazine publisher), and now we’re seeing at last one major mutual fund (Robur) being against selling.
The main challenge with Readly for me is that founders have left and early investors seem to be willing to sell. That is not unlike TradeDoubler many years ago when they had an offer from AOL, and Swedish mutual funds declined to sell. It will be interesting to see if the result will be the same.