Nordic-based financial services institution Nordea Bank said acquisitions helped fuel the growth of William Demant Holdings and Sonova Holding. William Demant is a Denmark-based hearing aid manufacturer while Sonova is the largest hearing aid maker in the world. From hold, Nordea now gave the buy recommendation to investors of the stocks of both firms.

Nordea Analyst Soren V. Holm Sorensen told Bloomberg, "Acquisitions have been a major growth driver in the hearing-aid industry in recent years. Sonova and William Demant have been able to gain significant market share through acquisitions."

Two of Demant's acquisitions were Amplivox and Grason Stadler. One of the purchases of Sonova Holding was Advanced Bionics, which was bought in 2009. 

The value of Demant rose to as much as 2.9% since May 7. The most recent close valued the shares at DKK 490.50 per share which placed the market value of the firm at DKK 27.8 billion or USD 4.9 billion. Meanwhile, Sonova increased to 1.7%, with shares trading at CHR 113.80 per share. The market value of the Zurich-based company is pegged at CHR 7.64 billion or USD 8.18 billion.