An index that tracks the cost of fine wine has continued on an upward trajectory this year as investors’ appetite for an alternative asset that is free from capital gains tax pushes prices, and returns, higher.

The Liv-ex Claret Chip index, which tracks the price of top-rated Bordeaux First Growths, was up 1.5% in July and 4.8% since the beginning of the year, as more people turn to wine as an alternative investment, according to auction house Sotheby's and The Wine Investment Fund.