Analysts are divided as to whether the sharp fall of close to 6% in the publicly-quoted sportswear company, Under Armour yesterday was exclusively linked to spectacular collapse at the Augusta Masters on Sunday of one of its principal ambassadors, golfer Jordan Spieth.

Investors were quick to offload shares in the US firm as the Masters favourite failed to retain his title.

However, this could also be a result of a downbeat forecast from Morgan Stanley, it warned that the Baltimore company's growth rate is unsustainable.

It advised that investors sell the stock and halved its target price for the company from $64 to $32.

Its main areas of concern are slowing demand in women's’ sportswear as the current 'athleisure' trend runs out of steam, and a slowing down in running shoe sales.

The company will issue its first quarter earning report on April 21st.

Under Armour has enjoyed strong growth in recent years, and surpassed Adidas as the second largest sportswear company in the US.