This candlestick alone means little without the context of the market. First you need to identify the current overall trend of the market. Ensure it is going in a direction and see how this pattern fits in. Secondly, you have to look at the news because this sell off could have been from a news release. If the news was not concrete, it could just be an emotional play in the market. Lastly, it could simply be people taking profits off the table.
These patterns on the chart should be used as a trigger to research more into the stock and see if there is value in your entering the market. With that, be sure to read up on the pattern and understand how others have implemented it into the market. Macroaxis has a wonderful set of tools to use and implement in your future research.