Finance minister P Chidambaram today dismissed "alarming predictions" that a bubble was building up in the stock market in view of the soaring Sensex, and said the government and market regulator Securities and Exchange Board of India (Sebi) were keeping a close watch on the developments."I do not accept these alarming predictions. Ours is oneof the best regulated markets. That does not mean there is no scope for improvement," Chidambaram said in the Lok Sabha today.He was responding in the zero hour to CPI member Gurudas Dasgupta who expressed concern over the "super hyper volatility" of the Bombay Stock Exchange and accused Sebi of not enforcing rules and government of sleeping over the matter.