The holy grail for investors -- and one being frantically searched for by technologists, entrepreneurs, and investors -- is to find a way to program machines to decipher social media (or more accurately, unstructured text) and structure a trading system around it. Sentiment analysis (the ability to pull out what people are feeling by the words they're using online) is one of the next big things in investing. Here are a few of the resources investors may want to consider when learning about sentiment analysis and portfolio management. Have any suggestions? Add your own below.