The VSA principle that markets, like a weighted coin, develop a directional bias once enough stock has been transferred between weak and strong holders. Accumulation weights the market to go up; distribution weights it to go down. The amount of accumulation or distribution determines how far the subsequent move can travel—a wide accumulation base produces a large mark-up, while a narrow base produces a small one. This is why point-and-figure charts (which measure the width of the cause) are used to estimate the height of the eventual mark-up or mark-down.