Why would the SEC have prosecuted this case if naked shorting never occurs?
An allegation of naked short selling was brought by the SEC against a broker-dealer in 2021. The broker repeatedly violated Regulation SHO, which requires brokers to mark all sell orders for stocks as either "long," "short" or "short exempt." The broker-dealer in question marked $250 million of short sale orders of a hedge fund as either "long" or "short exempt." https://seekingalpha.com/article/4453048-naked-short-selling
Just because something is illegal doesn't mean it can't exist. We have laws against selling illegal drugs, but it still happens all the time.
TenKay, re: [[ Then explain exactly how they are kept “hidden”? ]]
if shares are borrowed for short sale from within a brokerage then the brokerage is legally required to post the transaction for short interest stats.
the key assumption you're making is that brokerages don't cheat both the market and their customers.
look up the lawsuits schwab faced decades ago as an example of seemingly stupid crimes which never get punished because sec agents have no incentive to punish people who will give them golden tickets on early retirement.