The margin (credit) requirements in the US (see NASD Rule 3350) are the greater of $2.50/share or 50% of the price for stocks under $5. In Canada, (see IDA Reg. 100) the margin (credit) required is only $.50/share, so you'll have to have an account worth at least $500MM to orchestrate a retail short position of a billion shares.
Register for free to join our community of investors and share your ideas. You will also get access to streaming quotes, interactive charts, trades, portfolio, live options flow and more tools.