Citadel makes a huge profit by paying order flow fees. They pay over $1 billion annually in order flow fees, so it's safe to say their actual revenue is far higher (they're not here to lose money). The problem with blockchain-native stock markets for Citadel is that they use two-sided trading and atomic settlement. I place an offer, you place an offer. If you accept my offer (e.g., through a market order), that's the final price we settle. Market makers can't intervene between buyers and sellers. This is very disadvantageous for Citadel. Therefore, it's not surprising that they don't seem keen on deploying stocks natively on the blockchain, even if two-sided trading is possible. And it's not just market makers who are unhappy about this. Introducing brokers, prime brokers, DTCCs—they can't profit from it either. But I bet you can guess who will benefit… Natively public stock trading on a public blockchain, and trading in a self-custodied, self-settled market. Lending through DeFi, and cross-collateralization with other digital assets. This is the future direction of development, and it is coming soon.