Resolves as YES if Manifold bans "Permanent Stock" markets -- markets that allow users to bet on whether other users think a number will go up or down in perpetuity -- before 2030.
For example, an "Elon Musk" stock is supposed to go up when ... Elon Musk becomes more popular? I don't know. Because the idea is meaningless. A prediction market cannot really have perpetual "stock" markets because the fictitious securities on this website do not pay out until the question is marked as YES or NO or some other definitive market-ending result -- something that cannot happen in a perpetual market, and indeed something that doesn't even happen in the stock market.
According to Warren Buffett, the value of a company's equity is the time-discounted value of the profits that the company will generate before the company dissolves. A share of stock is a prortionate claim of those discounted profits. The price of the share in the market oscillates as people buy and sell. According to value investors, in the short term, price and value can become disconnected because of speculation and emotional trading, but in the long term, price and value converge. People who believe in the efficient market hypothesis (strong form or weak form) believe the market uses price discovery mechanisms to converge on the true value of the stock very quickly.
On the other hand, in a prediction market, a "stock" in a person is purely speculative. There are no "profits" that can be generated by the "stock." The markets, by definition, will not resolve, so you cannot be paid out $1 for a share.
Related questions
Actual companies have "anchoring events" when they issue dividends, stock buybacks, dilute their stock, activist investors buy the stock for voting rights, or they get bought by another company. So even if a company has none of these things going for decades, if the price randomly drops too low or too high there are ways for it to correct.
With prediction market "stocks", there's nothing to anchor it. Elon Musk could die tomorrow and his memestock could be trading at 90%.
Though, with hype-driven companies like Tesla, arguably the hype part of the valuation is similar to these since they're solely "will other people be convinced by a lofty vision to vote like me?"
Manifold takes such a hands-off approach that I think it is unlikely that this will resolve as YES. On the other hand, if they're interested in running a good website in the long term, they'll ban trashy, meaningless markets like "perpetual stock" markets in a person's "stock." I'm long NO at 50%, but I'd be happy to lose money on this.