A single custodian now controls the coinbase addresses of at least 9 pools, representing 47% of total hashrate.

As demonstrated by this consolidation of mining reward outputs from AntPool, F2Pool, Binance Pool, Braiins, btccom, SECPOOL and Poolin:

The same custodian also controls ULTIMUSPOOL and 1THash's coinbase addresses, and previously received mining rewards from Luxor.

(Luxor changed their setup immediately after I first tweeted about this in early December)

In other words, this one entity holds the keys to at least 47 out of every 100 freshly mined bitcoins.

Many of the same pools also provide hashrate for AntPool's transaction accelerator. And the custodian frequently accelerates large batch withdrawals using both AntPool and ViaBTC's transaction acceleration services.