Where can I find a list of the amount shares traded on margin per company?
I don’t think you will find shares traded on margin as a category.
Short sales are listed in Barron’s, which is an excellent source for data and ideas. Stock is shorted only in a margin account.
Futures on stocks are also traded only in a margin account.
Your question doesn’t make a lot of sense, and you don’t say why you’re asking it.
“Margin per company?” Do you mean per brokerage? Do you mean per stock? Do you mean per exchange?
I can’t imagine, even if you were able to obtain this info, how this would be beneficial to you, or to anyone to answer it for you.
You have to ask a valid question before you get an answer
Holistic pharmacist shares list of wacky health tips you may not have known