Understanding Relative Strength (RS) vs. RSI
Many traders confuse Relative Strength (comparing a stock to an index) with the Relative Strength Index (RSI). We break down the differences.
It is extremely common for retail traders to conflate Relative Strength (RS) with the Relative Strength Index (RSI). However, they are completely different tools measuring entirely different dimensions of market activity.
1. Relative Strength Index (RSI)
Developed by J. Welles Wilder, the RSI is a momentum oscillator that measures the speed and change of price movements of a single stock. It scales from 0 to 100 and is commonly used to identify overbought (>70) or oversold (<30) conditions.
RSI answers: "How fast is Stock X moving relative to its own history?"
2. Relative Strength (RS)
Relative Strength measures the performance of a stock or sector *relative* to a benchmark index (such as the Nifty 500). If Stock X rises by 10% while the Nifty 500 rises by only 2%, Stock X has positive Relative Strength.
RS answers: "Is Stock X outperforming the broader market?"
Why Relative Strength Matters for Sector Rotation
For sector rotation, RS is the ultimate indicator. We want to park capital only in sectors that exhibit rising Relative Strength. This ensures that even in flat or choppy markets, our capital is working in the most resilient assets that attract active institutional inflows.
