Shares of Barbeque-Nation Hospitality staged a smart comeback after a weak market debut and were locked in the upper circuit of 20 per cent at Rs 590.40 on the BSE in Wednesday's session. The stock of Barbeque Nation Hospitality, which owns and operates the popular chain of Barbeque Nation Restaurants, had opened at Rs 492, 1.6 per cent lower against its issue price of Rs 500 per share on the BSE. On the National Stock Exchange (NSE), the stock was frozen in the 20 per cent limit at Rs 587.80, after opening at Rs 489.85. Till 11:21 am, a combined 6.23 million equity shares had changing hands on the counter, while there were pending buy orders for 870,000 shares on the NSE and BSE.