The Securities and Exchange Board of India (Sebi) is examining the trading pattern in the stocks of state-run banks, following the announcement of the government’s recapitalisation programme on January 25. According to sources, the market regulator suspects price rigging by a group of investors. On January 25, the Nifty PSU Bank index, a gauge of the public sector bank (PSB) shares’ performance, had declined 6 per cent. Sources said the government raised the issue of declining share prices of top PSBs, despite providing capital to revive growth. When the Centre had first announced the Rs 2.1 trillion recapitalisation plan, the Nifty PSU Bank index had rallied 30 per cent on October 24.