CM Reference Rates Historical Prices and Methodology Updates

May 31, 2019

Overview

This post contains the following items:

Launch of Historical Prices for CM Reference Rates
Release of CM Reference Rates Methodology v1.1
Insights and Background on the changes included in the new methodology
Kraken duplicate trades issue
Publication of the CM Reference Rate Methodology online
Roadmap

Historical Prices for CM Reference Rates

As promised, Coin Metrics has launched historical reference rates for all 102 assets covered in CM Reference Rates
Historical reference rates can be found in the /referencerates endpoint of our API

Release of CM Reference Rates Methodology v1.1

Background

Coin Metrics launched the CM Reference Rates on May 15, 2019 using Methodology v1.0
The expectation was that Coin Metrics would gain insights into the functioning of the market upon launch and adjust our methodology and quality control processes accordingly
- Insights were primarily gained from the Quality Control Report, created by Coin Metrics as part of the CM Reference Rates Quality Control Framework
- The CM Reference Rates Quality Control Framework acts as the governing structure for all machine and human review and expert judgement
- A sample of the Quality Control Report is included at the end of this post
Consistent with that expectation, Coin Metrics has made the following modifications associated with the release of the CM Reference Rates Methodology v1.1

Insights and Background on the Changes

Data Contingency Rule Changes

The following changes were made to section 4.5 Data Contingency Rules of the Methodology:

Update to the second Data Contingency Rule: instead of using the price of the last observable transaction of the selected market before the start of the first time interval, use the next available time interval’s volume-weighted median price.
- This update was implemented to give greater weight to transactions that occur closer to the Fixing Time and address low-volume markets in which the last observable transaction before the start of the first time interval can be stale.
Update to the third Data Contingency Rule: instead of applying to any 1-minute time interval, only apply to any of the non-first or non-last 1-minute time intervals.
- The desired outcome was to select the 1-minute time interval closest to the Fixing Time. Thus, the first and last 1-minute time intervals will have dedicated logic (second and fourth Data Contingency Rules) and all other 1-minute time intervals would follow this rule.
- As part of the CM Reference Rates Quality Control Framework, Coin Metrics generates a Test Reference Rate for each of the three Fixing Times before the official Fixing Time
  - Thus, there is a Test Reference Rate generated for 23:00 UTC, 22:00 UTC and 21:00 UTC
- Coin Metrics felt that leveraging one of these rates, subject to the oversight and review requirements, would better represent the Reference Rate given the relative proximity to the Fixing Time as compared to the most recent published reference rate.
Update to the fourth Data Contingency Rule: instead of using the last published rate, use the last hourly reference rate in which there were trades during that hour’s Observation Window.
- As part of the CM Reference Rates Quality Control Framework, Coin Metrics generates a Test Reference Rate for each of the three Fixing Times before the official Fixing Time
  - Thus, there is a Test Reference Rate generated for 23:00 UTC, 22:00 UTC and 21:00 UTC
- Coin Metrics felt that leveraging one of these rates, subject to the oversight and review requirements, would better represent the Reference Rate given the relative proximity to the Fixing Time as compared to the most recent published reference rate.

Data Source Changes

The Quality Control Report noted instances of low liquidity and identified assets that are in danger of having insufficient trades in the 60-minute calculation window.
Low trades were observed for several reasons:
1. Trading activity during weekends is lower than on weekdays which affects a small number of infrequently-traded assets
2. Some stablecoins such as Dai and Gemini Dollar are susceptible to low trades because the CM Reference Rate Methodology selects markets quoted in USD, Bitcoin, or Ether. Special consideration is given to stablecoins where selected markets include markets where the stablecoin itself can be the quote currency and the base currency can be USD, Bitcoin, or Ether to match market convention. The methodology does not select stablecoin:stablecoin markets.
To address the low liquidity, several changes to the market whitelist were made — expanding the whitelist for some assets and contracting it for others. The net impact of these changes eliminated the issue of low trades in the calculation window for several assets.
1. In the case of additions, ratings produced by the Market Selection Framework were used to select the next best markets to add.
2. In the case of removals, expert judgment was applied to remove extremely illiquid markets with prices that differed materially from the other markets.
The changes to the whitelist were
1. WAX (WAX)
  1. added “upbit-wax-eth-spot”, “bitfinex-wax-eth-spot”, “huobi-wax-btc-spot”, “huobi-wax-eth-spot”
2. Odyssey (OCN)
  1. added “gate.io-ocn-eth-spot”, “hitbtc-ocn-eth-spot”, “gate.io-ocn-btc-spot”, “huobi-ocn-eth-spot”, “huobi-ocn-btc-spot”
3. FunFair (FUN)
  1. added “hitbtc-fun-btc-spot”, “hitbtc-fun-eth-spot”
4. Maker (MKR)
  1. added “hitbtc-mkr-eth-spot”, “ethfinex-mkr-btc-spot”, “ethfinex-mkr-eth-spot”, “ethfinex-mkr-usd-spot”, “bibox-mkr-btc-spot”, “bibox-mkr-eth-spot”
5. QASH (QASH)
  1. added “cex.io-qash-btc-spot”, “gate.io-qash-eth-spot”, “liquid-qash-eth-spot”, “gate.io-qash-btc-spot”, “huobi-qash-btc-spot”, “huobi-qash-eth-spot”
6. TenX (PAY)
  1. added “huobi-pay-eth-spot”, “huobi-pay-btc-spot”
7. Gemini Dollar (GUSD)
  1. added “bibox-btc-gusd-spot”, “bibox-eth-gusd-spot”
8. Bitcoin Diamond (BCD)
  1. added “hitbtc-bcd-btc-spot”
  2. removed “huobi-bcd-btc-spot”
9. Bytom (BTM)
  1. added “huobi-btm-btc-spot”
  2. removed “hitbtc-btm-btc-spot”, “hitbtc-btm-eth-spot”

Quality Control Report Sample

The below sample is for illustrative purposes only

Kraken Duplicate Trades

Issue Background

Coin Metrics collects trades from Kraken exchange via both WebSocket and HTTP
Coin Metrics noticed that Kraken trades received via WebSocket often had a different timestamp from the same trades received from HTTP
That, in turn, resulted in some trades received from Kraken being duplicated in the Observation Window

Impact and Resolution

Coin Metrics noticed and resolved this issue within 48 hours
Coin Metric’s robust Reference Rate methodology meant that the net impact of this issue was minimal
- Most assets were largely unaffected. For Bitcoin, resolving this issue resulted in a median absolute difference of 0.001 percent and the largest single-day difference is 0.005 percent. For Ethereum, the median absolute difference is 0.001 percent and the largest single-day difference is 0.001 percent.
- The largest median absolute difference was observed in Project Pai at 1 percent. The largest single-day difference for this asset is 2.5 percent.
However, out of an abundance of caution and transparency, Coin Metrics has recalculated and republished all Reference Rates for the impacted time period (May 15th to May 26th)

Publication of the CM Reference Rates Methodology online

One of Coin Metrics’ core values is to be open:
- We believe open data will empower the public to better understand, value, use, and ultimately steward public crypto networks
Consistent with that principle, we have added the CM Reference Rate Methodology to our website: https://coinmetrics.io/reference-rates/
Check it out and let us know what you think

Roadmap

Coin Metrics expects to make consistent updates to the CM Reference Rates product
In the short term, those updates may include
- Inclusion of more assets
- More publication times (New York, London, Tokyo close)
We will keep you updated on our progress

If there is something you would like us to add to our roadmap, let us know at [email protected]