It was the third straight session of loss for stocks on Wednesday as the Sensex took a hit of 216 points to close at a three-week low below the 32,000-mark on growing sense of disquiet following Sebi crackdown against suspected shell companies. The regulator clamped down on 331 such firms on Monday, directing exchanges to take action against them. Investors also ran for cover after a flare-up in tension between the US and North Korea over the latter's ballistic missile programme. They fear for the worse as both sides show no signs of backing down, according to traders. Selling pressure built up following muted June quarter earnings by some companies, they added. It was so strong that all the sectoral indices, led by healthcare and auto, ended in the negative zone. The Sensex recovered partially before settling down 216.35 points, or 0.68 per cent, at 31,797.84 -- its lowest closing since July 18.