In a market correction everything falls. But some names fall 15% and others 4%. The one that fell 4% did so because someone bought every dip — meaning there is real demand not dependent on general mood. When the pressure lifts, that name usually makes a new high first while the rest are still repairing.

Measuring needs no special tools: compare the stock's price change to the index's over the same window — three months and six months. Above the index in both means relative strength. Below it means any pretty pattern you find rests on weak demand.

It is not the same as the well-known relative strength index, which measures a stock against itself and flags overbought or oversold. The names are similar and the confusion is common. Here we compare against the index, and it measures leadership, not extremes.

It is also not a reason to buy on its own. Relative strength is a filter: it tells you who to look at, not when to enter. Timing comes from the pattern and the level.

The same logic works one layer up: check which sector has led over the past three months, and only then hunt for strong names inside it. A strong stock in a weak sector fights the current; an average stock in a leading sector gets carried up by it. Combining both — a leading sector and a leading name inside it — underpins most successful swing trades.