The pension fund has bought or picked up stakes in 300 companies since 1990

GNC

The biggest retailer of health and wellness products, it has had18 straight quarters of same-store sales growth.

SIMMONS BEDDING

Teachers', along with Ares Management, bought the mattress maker out of bankruptcy this year. The pension fund bought Serta Mattress in 2005.

MAPLE LEAF SPORTS & ENTERTAINMENT

The unit is teaming up with Ontario Teachers' real estate group on a $500 million development.

AQUILEX HOLDINGS

The company provides maintenance and repair services to energy-related businesses including oil refineries.

CADILLAC FAIRVIEW

Teachers' real estate subsidiary manages properties including the Toronto Eaton Centre and Calgary's Chinook Centre.

Data: Ontario Teachers' Pension Plan