A callable bull/bear contract, or CBBC in short form, is a derivative financial instrument that provides investors with a leveraged investment in underlying assets, which can be a single stock, or an index. CBBC is usually issued by third parties, mostly investment banks, but neither by stock exchanges nor by asset owners. It was first introduced in Europe and Australia in 2001, and it is now popular in United Kingdom, Germany, Switzerland, Italy, and Hong Kong.