I make algorithms for the Forex market. I haven't dived into BTC trading because each exchange has their own API ( commands ) and there is not a standardized trading platform for BTC trading yet. I know that fxopen and BTCE- both offer MetaTrader ( A trading platform that makes automated trading aka BOTS easily coded using c language) but their spreads and commission make trading Bitcoins inefficient and more difficult to make profit. 

Building/Designing the actual trading decisions for a fully automated and profitable algorithm takes most of all trading experience. Here is a list of my bots for Forex and these strategies could possibly work for Bitcoin - http://www.myfxbook.com/members/RedRhinolab