Known unknowns and unknown unknowns

As traders, we have to accept that we do not know what is going to happen in the future. While our chosen method would look to to profit from an 'edge', based on some form of probability or odds (e.g. trends tend to persist until they don't), we should never approach the markets with an attitude that we can be sure what will happen from one minute to the next, one day to the next, or one week to the next.

Price action in an individual stock, forex pair or commodity can change behaviour at any time.

Therefore, we must account for that possibility in our own method, our mindset and our attitude towards risk.