Not really, no. Equities, and equity indices, are comprised of productive businesses. They are positive sum because investor returns are generated by non-invest

Not really, no. Equities, and equity indices, are comprised of productive businesses. They are positive sum because investor returns are generated by non-investor participants (the customers of the business buying goods and services). A better analogy between crypto in traditional markets is some sort of wild-west futures market and options market. Index futures are provably zero-sum. Options are negative-sum for buyers, if I'm not mistaken.