SHANGHAI B shares bounced back on Friday following a difficult week sparked by the yuan's swap-centre devaluation. The Credit Lyonnais Shanghai B Index gained 5.13 per cent on the day to close at 757.58, but was down 10 per cent on the previous Friday's close. The shell-shocked Shenzhen exchange failed to shake its market bears, who dragged the Credit Lyonnais B Index 3.74 per cent lower to 1,018.33. Over the week, Shenzhen B shares fell 5.5 per cent. Newcomer FIYTA again failed to attract its first transaction on Friday, its second day of trading, and hapless Vanke slipped two more US cents to 96 cents. Vanke has fallen in every session since its May 28 debut. Domestic shares had a better week. The Shanghai A market registered a tiny gain from the previous Friday, with the Credit Lyonnais Index edging up 0.8 per cent to 6,733.09. This was despite a fall of 1.15 per cent on Friday. Shenzhen A shares gained 2.2 per cent on the week to end at 2,491.4. .