The trading of binary options is essentially predicting whether an asset price will go UP or DOWN over a period of time. A trader purchases an option and if the trader predicted the move correctly at the end of the option period, it generates approximately 70-80% return on the trader's investment. If the trader was wrong, the investor loses most of the money they had paid for the option. Binary options expiry times vary from 30 seconds up to more than 1 year.

http://cointelegraph.com/news/115002/binary-options-bring-immense-opportunity-for-bitcoin-users