How are the indices calculated?

We calculate our indices monthly. Therefore, one index movement per month summarizes all respective price observations. To summarize these price movements, we take the following approach:

• Selection of whiskies
  We select those whiskies from the current month that appeared in the most previous round of auctions. A "round of auction" is defined by a calendar month, i.e. all auctions closed within that month. This methodology prefers whiskies traded on auctions for some time and disadvantages new releases, for which we often observe erratic price movements at the beginning.

• The price movement of a single whisky
  We calculate the one-month price change for each whisky included in the index. For this purpose, we convert all prices to Euro. If the last price observation is farther in the past, we break down that price change to its monthly share by linearly interpolating the monthly prices. The "monthly price" is the average of all monthly price observations.

• Combining price movements to an index movement
  The index movement is the weighted sum over the one-month price changes of all included whiskies. The weight is defined by each whisky's "old" market value. We cap these weights to prevent an overweight of very expensive whiskies. The exact weight cap depends on the number of included whiskies but never exceeds 20%.

The maximum number of whiskies in each index movement varies between the indices and is displayed on the respective index page. We require at least ten whiskies to be traded to calculate an index movement. Otherwise, the index stays unchanged.

For the Whiskystats Whisky Index (WWI), we cap each brand's weight at 10%. A brand's weight is the summed weight of all whiskies from that brand. This ensures that the WWI is a general market index and not dominated by one or two major brands.