Bottle index

Definition

Flaskeindekset is a reference index that measures the change in the average price for a curated selection of rare whisky bottles over time. The index is based on realized transaction prices in the secondary market and provides a comparable indicator of price development rather than individual sales.

Formål

Flaskeindekset is used as a market reference for collectors, investors and media. It helps identify general price trends, compare bottle types and assess market sentiment for rare editions.

Datagrundlag

Data are collected from:

• Auctions (live and online) and fixed catalog transactions

• Specialty retailers and online marketplaces

• Private sales, when transaction documentation is available and verified
  Data are cleaned and standardized: primarily realized prices, volume and provenance are checked; obsolete transactions without unambiguous identification or with missing verification are excluded.

Beregning og konstruktion

For each period t, price relatives are calculated for bottles in the index list:
r_i,t = P_i,t / P_i,t-1
Where P_i,t is the realized price for bottle i in period t.
The bottles' weights w_i are fixed at the outset and reflect the bottle selections' market leadership and volume (e.g., turnover or number of registered transactions).
The overall index relative i_t is calculated as a weighted average:
i_t = Σ_i w_i * r_i,t
The index is updated as:
I_t = I_{t-1} * i_t
Base year and base value: I_0 = 100, often set to 100 at a fixed reference year (e.g., 2010-01).
For robustness, outliers are handled through trimming or robust statistics.

Praktiske anvendelser

• Track price development for rare bottles over time

• Compare market-leading bottles and editions

• Support investment and collecting decisions

• Prepare market reports and journalistic analyses

Eksempel

Assume base I_0 = 100 for period t = 0.
Bottle A: price in period t-1 = 2000, price in period t = 2400 (r_A,t = 1.20), weight w_A = 0.6
Bottle B: price in period t-1 = 1200, price in period t = 1260 (r_B,t = 1.05), weight w_B = 0.4
Total i_t = 0.61.20 + 0.41.05 = 0.72 + 0.42 = 1.14
I_t = I_{t-1} * i_t = 100 * 1.14 = 114
This illustrates a price increase of 14% in the period.

Begrænsninger

• The market for rare bottles is illiquid and volatile; the index is sensitive to a few large transactions.

• Data selection and provenance can influence the result; discrepancies in registrations require strict quality control.

• New editions, changed packaging or changes in retailer practices can lead to temporary fluctuations in the index.

Se også

• Whisky Price Index

• Auction figures and price development

• Collector and investment analysis in spirits