A line chart connects a series of data points and is used by traders to monitor prices, currencies, indexes, and other data.

Suppose, for example, that in the chart above the box size was $50 instead of $5. ... three-line break charts help smooth out volatility by focusing on price ranges or breakouts.

Knowing when to sell a stock is half the battle of investing. Use the upper channel line break to lock in gains after big upside moves.