Pricing Strategies

Data Collection

First we collect data from some of the most trustworthy NFT marketplaces (Opensea, LooksRare, X2Y2). And we monitor the price changes from their official NFT floor price API.

Outliers Detection

To ensure the NFT marketplace data is correct, Zero or other error data will be removed from the calculation.
Next, we remove prices that falls outside the reasonable range. We assume the prices from different marketplaces conform to the normal distribution during a particular time period, which means they should not have wide swings at a checkpoint, so the range is calculated using the standard deviation. Prices that falls outside 1.5X standard deviation will be considered as outliers and removed from the calculation.

Price Calculation

Then, we calculate the arithmetic mean of the filtered data and submit it to the oracle contract.

On-chain Data Protection

Apart from the off-chain pricing strategies, we also designed on-chain data protection mechanisms to ensure the on-chain oracle security.
  • The fluctuation between two updates cannot exceed 15%.
  • The interval between two updates cannot be less than 30 minutes.