Easy-To-Borrow List

See: Borrow. That term refers to the interest costs and covenants that a given brokerage will charge its client, who is trying to borrow securities from it to short or sell, betting that the underlying stock's price will go down. So what would hard-to-borrow be, then? Well, if a stock were illiquid...like, very few shares traded per day, and/or it was extremely volatile, that'd make it hard-to-borrow (translation: expensive to the client).

Why?

Like, why would a brokerage even care? Well, if a stock trades only a million shares a day, and a client wants to short 5 million of them, then you can imagine if, say, GOOG ends up wanting to buy them, the stock could go from $18 to $50 really fast, wiping a massive short position of 5 millon shares times a loss then of $32 x 5 million = $160 million. That'd be a huge loss for a small fund in a very short time. So it makes sense to the brokerage to push back, such that five full days trading is just too much to allow for a given short.