Nigeria's share index climbed to a 20-month high to the cross 27,000 point threshold on Thursday, driven higher by gains in banking and commodities stocks.
Shares in Diamond Bank rose 9.83 percent to 4.47 naira per share, their second day in a row of rising almost the maximum 10 percent allowed, boosted by strong earnings.
The lender on Tuesday said its nine month pretax profit hit 23.2 billion naira, up from a loss of 6.9 billion naira during the same period a year ago.
Diamond Bank is one of the 25 stocks eligible for market making under a new stock exchange system meant to boost liquidity, so its share price can rise up to 10 percent a day, up from the old 5 percent limit that still holds for most stocks.
Nigeria's share index has gained almost 30 percent this year, one of the best performing frontier markets in Africa. The last time it went above 27,000 was February 2011.
Other gainers included heavyweight Dangote Sugar, and Sterling Bank up more than 9.5 percent each.