Cenkos Securities posts pre-tax profits of £1.7 million for the six months to the end of June - 91% down from £18.6 million a year ago.
Profit after tax decreased by 96% to £0.7 million (H1 2015: £14.6 million) and basic earnings per share fell by 95% to 1.2p.
Revenue for the period decreased by 71% to £15.3 million (H1 2015: £53.1 million).
In H1 2016 thr group raised £529 million for clients (H1 2015: £2,020 million - including £1,029 million for BCA Marketplace plc).
Excluding the impact of this large deal in 2015, the 42% fall in revenues reflects quieter equity markets - including AIM - than those experienced in H1 2015.
Against the backdrop of the Brexit vote and wider European macro-economic uncertainty, total funds raised by AIM companies fell by 30% to £1,931 million in H1 2016, when compared to H1 2015 (source: LSE AIM factsheet June 2016).
Chief executive Jim Durkin said: "Our successful strategy of being a leading UK institutional broker to growth companies and investment funds has led to us being profitable in every year since our formation in 2005 and this continued into the first half of 2016 in spite of very difficult market conditions which meant a number of significant fundraisings slipped into the second half of 2016. Since formation in 2005 we have raised in excess of £15 billion of equity capital for our clients.
"We believe that, as one of the leading brokers in London for growth companies, we are well-placed to benefit from improvements in market conditions and have made a good start to the second half of the year. There is institutional demand to fund high quality companies and ideas and since July we have been engaged in relation to a number of significant fundraisings and our current pipeline is encouraging."
At 1:06pm: (LON:CNKS) Cenkos Securities PLC share price was -13p at 102p