These equity transactions aren't as simple as buying and selling an ETF though. Moreover, most of the existing sales have been private, so sellers (e.g. accredited investors) and buyers (e.g. employees and founders) are at a steep information disadvantage when jumping into these deals-- Carta and Forge know the consequences, but the market participants do not. Moreover, the space isn't necessarily well-regulated. So that's a prime business opportunity: you have people who are too "dumb" to create a market themselves, but who want to transact. The snark in my narrative comes from personal observations that it's very easy to get burned (even in successful exits) and that these middlemen are typically even less trustworthy than big banks.