Why stock market's close is now an auction - explained
For over three decades, the closing price was the volume-weighted average (VWAP) of all trades between 3:00 pm and 3:30 pm. Nobody actually traded at that price. It was a calculation, not a transaction. For long-term investors, nothing changes. For index funds and traders, the closing routine is now different.
We haven't written up this one. Times of India has the full story — the link below goes straight to it.