Stocks globally have retreated in recent weeks after months of recovery, due to concerns about property developer China Evergrande and rising inflation, pushing the CBOE volatility index, or Wall Street's fear gauge, to a four-month high.
"We closed the first six months (of 2021) with a pickup in market volatility and client trading volumes following what was a more subdued environment from the start of the year," CMC Chief Executive Officer Peter Cruddas said.
CMC rival Plus500 Ltd on Monday raised its annual forecast again, saying it saw further positive momentum in the third quarter.
CMC also maintained its annual profit outlook of 250 million to 280 million pounds ($340 million to $380 million), which it had cut last month due to subdued volatility.
It said active clients during the first half of the year were slightly below year-ago levels.
First-half operating costs, excluding variable pay, are expected to be about 84 million pounds, up from the 79 million pounds reported a year ago.
($1 = 0.7363 pounds)
(Reporting by Aby Jose Koilparambil and Muvija M in Bengaluru; Editing by Rashmi Aich)