Who writes price feeds on-chain?
Pyth Network uses a pull-based design, with prices submitted by first-party publishers such as trading firms and market makers. Chainlink Data Feeds are representative of a push-based model, in which a group of independent nodes aggregate quotes and write them on-chain.
The advantage of the push-based model is that contracts can use the data straight away. The trade-off is that the oracle network must continuously pay gas to push updates, so the update frequency cannot be increased arbitrarily.
$PYTH is the token of Pyth, a pull-based oracle network.

#PYTH

The above is compiled from public information. Please refer to the original text.