Nifty 51 instead of the usual 50 constituents? This is not the first time—read more to find out

For new investors, the math would have looked off today—seeing 51 constituents in the Nifty 50 index. The oddity came after the Tata Motors’ demerger, which listed its commercial vehicle arm today.

 But this is not the first time that the benchmark index has seen such an anomaly. In fact, in January this year, ITC decided to diverge its hotel business from its core business, and was a part of the Nifty 50 index for a few days.

Why does this happen?

R. Ponmudi, Founder and CEO, Enrich Money said that the Nifty 50 briefly expanding to 51 constituents is not a glitch. “It’s a smart safeguard built into India’s market architecture. By allowing Tata Motors’ demerged entity to coexist temporarily, NSE has ensured that passive funds remain stable and index continuity is maintained without creating unnecessary volatility.” According to him, this step is a quiet but meaningful win for India’s market systems where structure, not speculation, protects investor confidence.

Does this accommodation affect the weightage?

Ponmudi says that the impact on overall weightage is marginal. “The combined value of Tata’s passenger and commercial vehicle entities still accounts for roughly the same share around 1.5% of Nifty’s total weight so it doesn’t distort the broader index balance. What it does show is how the system absorbs change without shaking investor trust.”

Then why does the BSE Sensex index not show 31 constituents like the NSE Nifty 50?

The BSE Sensex follows a different methodology. Ponmudi explains that it adjusts its divisor directly instead of temporarily expanding constituents. “The Nifty framework prefers operational flexibility, while the Sensex emphasizes mathematical precision. Both approaches are right for their design philosophy, but the Nifty’s method stands out for its ability to handle India’s increasing wave of demergers and corporate restructurings smoothly,” he says.

Therefore, Tata Motors Limited, the commercial arm will be a part of the Nifty 50 index, till a rebalance happens. As per BSE, the company’s share will be under the trade-for-trade segment for the first 10 sessions for smooth price discovery. The newly listed CV arm’s inclusion in the Nifty 50 will be dependent on certain factors like market capitalization, trading liquidity and free-float.