Risk and portfolio manager. Former long/short hedge fund manager and prop trader. 20 years of market experience. Started career on Wall Street in the heady 1990s. MBA in Finance from NYU Stern. @seeitmarket contributor. Opinions are my own.
Google offers a latent semantic indexing keywords tool that is extremely effective and it is free. The only way you can effectively do keyword research is using a tool built to exhibit all the relevant search phrase which would be the most famous.