Supertrend

Supertrend plots one line. In an uptrend the line is the lower band, under price. In a downtrend it is the upper band, above price. The band is a multiple of ATR away from the bar's midpoint, so it widens when volatility rises. A close through the line flips the trend. The default 10 and 3 is a convention, not an optimised constant.

A larger multiplier sits farther from price, flips less, and gives back more of the move before it exits. A shorter ATR length reacts faster to a volatility shock. The line ratchets: in an uptrend the lower band does not fall just because one bar dipped. It stays until price actually closes through it.

Line under price, often drawn green, is the long regime. The line is a trailing stop. Pullbacks that do not close through it leave the regime intact. A flip to the other side is the exit.

Line above price is the short regime. Same mechanics. Supertrend does not grade the quality of the trend. A choppy market will flip it. Do not add a second opinion from the same ATR and call it confirmation.

Optimising 10 and 3 into odd numbers on one symbol and expecting that pair to travel. Also using Supertrend flips against a higher-timeframe trend without a stop beyond the line.

It is a trend tool based on volatility, so in a range the flips are the losing trades. It will not identify support. It will trail whatever direction last won until it loses.