According to the StakingRewards (as of October 3rd, 2021), the staking market cap is currently at $633BN, with $146BN locked in staking with an average reward rate of 14.95%. PoS dominance is 58.68% and is expected to grow once Ethereum completes its transition to Proof of Stake.
The considerable PoS hype is spearheaded by Ethereum's move from PoW towards a PoS-based network. Ethereum is the second biggest coin on the cryptocurrency market and the underlying blockchain for the vast majority of DeFi (Decentralized Finance) tokens and NFTs (Non-fungible-tokens).
The PoS market is also experiencing a revival through blockchain ecosystems like Polkadot, Cosmos, or Kusama. The blockchain-as-a-service hubs foster innovation, cross-chain interoperability, and quick launch of new PoS projects with vast staking opportunities.