AMC Entertainment Holdings Inc (AMC)

[bio33]

There is cuspid number for every stock issues that is real. The dtcc responsibility is to track shares by numbers . Therfore your broker can loan out your shares under certain circumstances but shares are still registered with your name. Now Google naked shorting (see below) Investipedia and you will get a more though understanding of how stocks are loaned out and shorting process
Gltu and all amc retail investors

see below some sites
https://www.investopedia.com/terms/s/shortselling.asp

https://www.investopedia.com/terms/n/nakedshorting.asp#:~:text=Naked%20shorting%20is%20the%20illegal,before%20they%20sell%20it%20short.