The market cap of NFTX is not directly provided in the given articles, but NFTX is described as a platform that aims to create a liquid market for illiquid NFTs by issuing index funds and converting NFTs into ERC20 tokens for easier trading. The success and potential market cap of NFTX could be inferred from its ability to attract users, the value of NFTs it manages to tokenize, and the overall growth of the NFT market.