AMG borrows money to buy asset managers that invest in equities. When equity market fall, AMG's revenue declines with the lower assets under management. Yet, the company still pays interest on its borrow debt.
Part of AMG's growth strategy is buying small to mid-sized asset managers. AMG must find asset managers and the current owners must accept to be purchased. If AMG can't find acquisitions or pays too much, it will hurt the company's growth.