One of the founders of premium drinks Fever-Tree is now £73 million richer, after selling a 3.9 percent stake in his company.

Deputy chairman Charles Rolls sold almost double the amount of shares he planned to sell, offering 4.5 million shares at £16.25 each. The larger-than-anticipated share sell-off followed “significant” demand from investors.

Rolls retains an 11.2 percent stake in the business, which he founded with chief executive Tim Warrilow.

The premium drinks group has seen an impressive performance on the stock market since its floated towards with end of 2014. Its share price has rise 900 percent since the IPO, rising more than 50 percent his year alone.

In its preliminary results for 2016, Fever-Tree profits soared to £34.3 million last year, up from £16.8 million in 2015, marking an increase of 105 percent. Fever-Tree’s international sales have expanded rapidly, and more than 50 percent of its revenues now come from outside the UK.

Fever-Tree (LON:FEVR) shares are currently up 0.96 percent at 1,728.50 (1116GMT).