Base Goes ZK, Polygon Unlocks Private Stablecoin Transfers, Kalshi Hits $22B Valuation in Mega Raise!

A dense week of infrastructure upgrades and capital moves across the crypto stack. Base is adopting zero-knowledge proofs for finality, a shift that would let the Coinbase-backed L2 settle state transitions cryptographically rather than relying solely on optimistic fraud-proof windows — compressing…