Many people around the world, after the subprime crisis more so , equate correlation with charlatanism. May be , but should that stop anyone from understanding data, not really. Knowing whatever metric about the unknown is much better than just having an intuitive feeling of things. Sometimes having a wrong map while exploring is OK, atleast it gives one confidence to venture and try things out. Taylor effect is one such aspect about correlation.

“To reach a port, we must sail - sail, not tie at anchor - sail, not drift. " -Roosevelt

NSE in its new circular has dropped about 25% of the stocks from Futures and Options Segment. Well before the number surprises you, the actual numbers are not that terrifying considering that the whole equity F&O market itself is small as compared to developed countries. There were only 252 stocks that were allowed to be in F&O segment at the beginning of the year. 68 stocks have been dropped in this year citing liquidity reasons, stock manipulation etc.

Bid ask spread movement is an interesting metric to track in a day. It has been observed in developed markets that it follows a U shaped pattern More details in this paper :Limit orders and Bid-Ask Spread In Indian markets case, came across a 3 pager in Economics and Political weekly that says that the bid ask spreads do follow the same U pattern. Link : Are you getting a good deal?

“The best thing about the future is that it comes only one day at a time” - Lincoln