Merriam-Webster's Dictionary defines greed as simply, "... a selfish and excessive desire for more of something (as money) than is needed." Greed is often referenced as one of the main contributors to trading loss. Greed mangles the mind by distracting the trader from what matters most in the trade, which is quite frankly, to protect your capital by prudent planning and following rules. It also distorts your judgment regarding high probability strategies and effective follow-through.