1. A system comprising: a topic extractor configured to: select a document that is pertinent to a topic based on searching, using a key phrase, a plurality of documents, identify an identifier of a party to a transaction being referenced in the document, the identifier of the party to the transaction being associated with the topic, and identify the transaction conducted by the party to the transaction based on the document; and a sentiment analyzer configured to: determine a rating of the transaction conducted by the party to the transaction based on the document, a determining of the rating of the transaction conducted by the party to the transaction including identifying, from a plurality of polarity words included in the document, a dominant polarity word based on a syntactic distance between the dominant polarity word and the topic in a syntactic tree, the dominant polarity word having a dominant polarity impact on the rating of the transaction conducted by the party to the transaction, and determine, using at least one processor, a sentiment of the document based on the transaction conducted by the party to the transaction associated with the topic, and the rating of the transaction conducted by the party to the transaction associated with the topic.