If people want to understand what synthetics mean to me in this context, see the staff statement on tokenization, which distinguishes tokenized versions of issuer-sponsored stocks and of stocks that SEC-registered firms hold for their customers from synthetic instruments that provide exposure to stocks. https://www.sec.gov/newsroom/speeches-statements/corp-fin-statement-tokenized-securities-012826-statement-tokenized-securities(Hester Peirce)