JOHANNESBURG (Reuters) - African Bank was among the biggest gainers on a firmer South African stock market on Friday despite flagging a 90-percent plunge in full-year earnings due in part to rising bad debts among its core market of low income borrowers. The overall market has taken a cautiously upbeat tone once more after nine straight days of gains - which took it to record highs - were snapped on Wednesday, in part by technical factors which suggested it was due for a correction. "The underlying mood is still bullish and I am a firm believer that the market kind of pushes higher towards the end of the year," said Evan Giannakis, a equity dealer at Imara SP Reid. "There's hasn't been any bad news coming out but at same time we have pushed up quite hard and we are approaching the fourth quarter, which is quite strong for the JSE." The JSE Top-40 index was up 0.18 percent at 40,314.88 and the broader All-share index gained 0.13 percent to 45,124.04. But the 14-day RSI, a momentum indicator tracked by technical analysts, for both the Top-40 and the All-share show the market remains close to overbought levels. African Bank, the nation's biggest unsecured loans lender, closed up 2.7 percent to 17.35 rand. It issued a second profit warning in five weeks on Friday, saying it would barely make money this year, sending its share price on a wild ride. Its shares had initially fallen by as much as 8 percent on that news before rebounding. Advancers outpaced decliners 171 to 158, according to preliminary bourse data, while 51 listings were unchanged with 148 million shares changing hands.