Sensex churn and change: How the index is like the Ship of Theseus

A quarter of the stocks have been replaced since 2019, marking the evolution of India's economy

The ancient Greeks argued a paradox: If the Ship of Theseus had all its wooden planks replaced one by one, in the end is it still the same ship?

Similarly, the S&P Sensex has had its constituents change over the years. The churn has continued amid new all-time highs – a quarter of the stocks have been replaced since 2019.

The methodology to include stocks in the index has changed over time. Earlier, the full value of listed shares was used. Since 2003, only the value of shares available in public hands is considered. More than