AIM Trimark Investments on Tuesday announced the capping of one of its most successful funds.

Effective May 30 at 16:00 ET, AIM Trimark will close the $1.3 billion Trimark Advantage Bond Fund to new investors. The fund, a top performer in the Canadian high-yield bond fund category, has received over $250 million in new cash during the first four months of the year and now represents over 40% of high-yield bond fund category assets.

“Saying no to new investments is never easy, especially when a fund is selling so well,” said Patrick Farmer, chief investment officer and executive vice president at AIM Trimark, in a statement “but investors’ interests must come first.”

Although the fund’s portfolio managers Rex Chong, Vince Hunt and Anthony Imbesi continue to believe high-yield bonds represent an attractive long-term investment opportunity, the portfolio management team is concerned they may have trouble finding a suitable number of acceptable high-yield bonds if present inflows are not curbed.

“Rather than compromise our high standards of credit worthiness and other critical measures applied to holdings in the fund, we chose to put investment discipline first,” said Farmer.

Existing unitholders continuing in the fund will be allowed to purchase additional units in the fund and maintain their existing investment options such as pre-authorized chequing.

Investments from transfers in cash and purchase orders from new investors of the Fund will not be accepted if they are received after May 30, at 16:00 ET.