AGRICULTURAL EDUCATION 1700
This rule can decrease the NUMBER of losses you experience. As simple as that sounds, it's one of the most often violated principles of good trading habits. So often is this rule broken that we are all familiar with cute little descriptions such as "catching a falling piano", or "reaching for a falling knife." What you use for this confirmation is your own affair; price rise or fall, momentum, frequency of trades or bid / ask "size" are just a few ways. Personally I combine them all (more or less), developing a 'feeling' about the confirmation, rather than a measurable quantity. However you choose to define confirmation, let experience be your best teacher here and do NOT enter the trade until you're convinced the stock is moving your direction!
RULE 2. When you are filled on the entry, place a STOP loss to minimize your potential for loss.