Utilize your financial knowledge, give your answer or opinion to the input question or subject . Answer format is not limited.

What are some important factors to consider before investing in a stock/index fund and why?
Goal - What is it that you are saving or investing to have: Educational costs, retirement, vacation, home, or something else. Dollar figure and time period would be the keys here. Risk tolerance - What kind of risks are you prepared to accept with the investment choices you are making? What kind of time commitment do these investments have and are you prepared to spend the time necessary for this to work? This is about how wild are the swings as well as what beliefs do you have that may play a role here. Strategy - Do you know what kind of buy and sell conditions you have? Do you know what kind of models you are following? This is really important to have before you buy something as afterward you may have buyer's remorse that may cause more problems in a sense. Record keeping - Do you know what kinds of records you'll need for tax purposes? Do you know how long to hold onto records? Those would be the main ones to my mind.