3. Traders often use the repo market to obtain specific securities to cover short positions. If a security is in short supply relative to demand, the repo rate on a specific security used as collateral in a repo transaction will be below the general (i.e., generic) collateral repo rate. When a particular security’s repo rate falls markedly, that security is said to be “on special.” Investors who own these securities are able to lend them out as collateral and borrow at bargain basement rates.

4. Suresh E. Krishman, “Asset-Based Interest-Rate Swaps,” Chapter 8 in Interest-Rate Swaps.