http://whirtorrgetftvz4g466sjqkegtyi35bjl4bvotfkfossunf5my4x6ad.onion/blog/anonymous-bitcoin-exchanges
Binance used to be one of them for instance, but now is stricter with the verification process. The same can be said about Kraken or KuCoin. Out of all of these, KuCoin seems to be the best when it comes to anonymity, however, in recent weeks there have been some allegations connected to insolvency of this exchange, so people should not hold significant amounts of capital in their KuCoin account.