Global head of distribution Warren Tonkinson said the fund was designed with limited capacity from its inception, owing to its focus on mid and small-sized companies.
When funds targeting relatively smaller companies grow too large, they can be forced to invest in too many companies at the same time and struggle to continue to outperform their rivals.
“As part of our ongoing capacity management, we have advised the fund’s clients that we are limiting subscriptions,” said Tonkinson.
“Where clients are unable to limit subscriptions, we have asked them to make the fund unavailable to their customers, until further notice.
“We believe this is in the best interest for all of the fund’s investors.”
The fund, which buys UK equities both ‘long’ and ‘short’, has gained 192.1% in the past years. This compares to a FTSE 250 Excluding Investment Trusts index gain of 121.95%.