Cryptocurrency exchange Bullish, backed by Peter Thiel, has confidentially filed for an IPO in the US, following eToro and Circle's success.This would be Bullish's second attempt to go public, with the IPO size and valuation yet unknown.Prominent investors like Peter Thiel and hedge fund giants back Bullish, which launched services in December 2023 and acquired CoinDesk.Other crypto companies like Gemini, Ripple, Kraken, and Consensys are also considering going public after eToro and Circle's recent IPOs.