Stock market indices, the Sensex and the Nifty, touched historic highs during the week ended October 19, but the markets snapped an eight-week rally after Sebi issued a discussion paper on limiting foreign inflows via participatory notes (P-notes).The Sensex crossed the 19,000-mark for the first time during the week and touched an all-time high of 19,198.66, following stability on the political front. The Sebi move prompted heavy selling by foreign institutional investors (FII), and the Sensex ended the week at 17,559.98 - down 859 points (4.66%) at 17,559.98.