Market price - also called 'market value' - refers to the most recent price a security sold for on an exchange or OTC, or its most recent bid and ask prices. This price is often different from the security's book value, which reflects the price on issue or when acquired. Also, more generally, the price of anything as determined by buyers and sellers in an open market.
Compared to book value, which remains static, market price is dynamic and reflects the ongoing supply and demand for the security. Mark to market accounting, based on valuing securities at market price rather than book value, has continued to expand despite accusations that the practice exacerbated the credit crisis for some financial institutions during 2008. The market price for liquid securities like gold and forex can be seen as a live ticker on some websites.