A P&F Buy signal occurs when a column of X's rises above the top of the previous column of X's. Point and Figure charts plot rising prices as columns of X's and falling prices as columns of O's, ignore time, and add a new column only on a reversal of several boxes, which filters out minor moves. This basic Point and Figure signal shows that demand has overcome supply at the prior high, and it is the building block of more complex bullish patterns.