Feb 10, 2022
Qtum Mainnet Staking Update
In the early days of the Qtum blockchain, I wrote many blogs about the staking characteristics and results for the blockchain. Here is a January 2022 update on all the stakers and results.
For this blog, we use the data set for one month of results from January 1 to January 31, 2022, with 83,703 blocks. From earlier reports, the main change is the addition of super stakers, delegate addresses, and 32-second block spacing, so we provide those details.
With 32 second blocks the blockchain averages 2,700 blocks a day, and after the halving on December 1, 2021, there are 1,350 QTUM in newly minted QTUM for block rewards each day.
TL;DR — Just the numbers for January:
- 2,158 unique stakers, 25 active super stakers, and 274 active delegated addresses.
- Addresses delegated to super stakers accounted for over 50% of the blocks.
- Network Weight 6.4 million, annual return 7.5 %, inflation rate 0.47%, real annual return 7.03 %.
- 32-second average block spacing, many shortest blocks with 4-second spacing, the longest with a 7-minute spacing.
Network Weight
Network weight is used only to calculate the “expected time” which is an estimate of the time to a block reward for a wallet — Reference 1. Network weight is an estimate of the total number of QTUM being staked, a number that cannot be precisely known for a permissionless network. Network weight is calculated based on recent block difficulties, where the difficulty number gives how “difficult” it is for a staker to publish the next block. Details of the Network Weight difficulty calculation are given in Reference 2.
The chart of Network Weight for January, smoothed with a 100-block average is:
Even with the Network Weight smoothed in the chart above, there is considerable variation characteristic of fully-decentralized consensus processes. The Network Weight is derived for each new block, and in January the range for Network Weight for individual blocks was 3.2 million to 11.4 million.
Over the 83,703 blocks in January, the average Network Weight was 6,400,186 or 6.4 million. We can plot the annual staking return vs. Network Weight as:
This chart shows with the average Network Weight of 6.4 million in January, the annual staking return was 7.5%. Given the current rate of newly minted block rewards of 486,000 QTUM per year, Qtum has an inflation rate of 486,000 / 104 million total supply = 0.47%, giving a real annual staking return (based on January) of 7.5% — 0.47% = 7.03%
Staker and Delegate Addresses
In January, super stakers got 50.2 % of the block rewards for their delegated addresses.
There were 25 active super stakers that received a block reward for their delegates in January.
There were 274 delegated addresses that received a block reward from their super staker in January.
There were 2,158 unique staker addresses (including super stakers) that received block rewards in January. This monthly number is up from the analysis before FastLane 32-second blocks because it is now quicker for smaller wallets to receive block rewards.
Block spacing
The current Qtum “FastLane” blockchain has target 32-second average block spacing. For all the blocks in January, the average was 31.998853 seconds.
Qtum Proof-of-Stake consensus is calculated for 4-second intervals, which means blocks may have spacings of 4 seconds, 8 seconds, 12 seconds, etc. The distribution of block spacings for January is:
This histogram chart shows the number of blocks in January with 4-second spacings, the number with 8-second spacings, etc.
Looking at the block spacings in more detail, there were 16.7 % of the blocks with 4-second spacing, and there were 67.0 % of blocks with 32-seconds or fewer spacings. For January, there were 8 blocks with 320 seconds or greater spacing (e.g., 10x the target of 32-seconds) and the longest block 1,520,246 had a 7-minute spacing.
References
1. Previous blog on Network Weight https://jb395official.medium.com/network-weight-october-31-2018-35795dc5bebd
2. Synopsis for Network Weight calculations based on FastLane Qtum Core v0.20.4, Feb. 2022.
The sum of recent difficulties and some calculations are in GetPoSKernelPS()
The estimate of time to a block reward “expected time” is calculated in updateStakingIcon()
The network weight calculations can be simplified to:
Network Weight = (sum 72 recent difficulties) / 2304 * 4294967296 * 4 / 100000000
which is the 72-period moving average of difficulties
divided by the target time for 72 blocks = 72 x 32 = 2304 seconds
times 2 to the 32nd power, a scaling factor = 4,294,967,296
times 4, for 4-second intervals
divided by 100,000,000, the number of Satoshis in one QTUM
