You can use the Snap to Price trend line option to draw a trend line whose end points automatically snap to the highest or lowest price for each trading day.
NOTE: You can also create the following types of trend lines:
Trend lines can be used to mark the strength of price action for a security over a period of time. These strength areas are known as "resistance" at the top-end of the range of trading, and "support" at the bottom-end of the trading range. These trading ranges can develop over short or long periods of time, depending on the fluidity of the stock.
You can draw trend lines on the Chart window to mark high and low points, thus dividing the chart into Support and Resistance zones. These zones can be used to determine entry and exit points in the market.
Resistance - The price a stock can trade at, but cannot exceed, for a certain period of time.
Support - The price stock trades at, but does not go lower than, for a certain period of time.
NOTE: To draw a Snap to Price trend line in the Chart window, you must display the Chart toolbar. To display the Chart toolbar, right-click the Chart window and select Show Toolbar from the Chart window pop-up menu. Click here for more information.
Perform the following to create a snap to price trend line:
From the Chart
toolbar, click 
.
NOTE: If you do not see this button, you need to display
the Chart toolbar.
Place the cursor over the position you want the trend line to begin.
Click and hold down the mouse button.
Move the cursor over the final day the trend line should include.
Release the mouse button. The new trend line appears on the chart.