The market-wide amount of stock borrowed on margin, sold short, and not yet covered (unit: lots). A description of market state; it does not constitute any directional view. Margin short sales are largely a retail borrow source.
The market-wide amount borrowed through securities lending (mostly an institutional borrow source), sold short, and not yet covered (unit: lots). Margin short and SBL short together describe the structure of the market's short-side balance.