There are a lot of indicators for ranking exchanges. The trading volume is usually one of the most used. But as we know this can be faked in a lot of cases.
BTC holding of exchanges are telling a nice the story.
As we see Binance comes on top here with more than 550k Bitcoins on their balance. Coinbase is next with more than 400k. These two are usually ranked as the two biggest in most other parameters as well. But usually Binance is leading by much more. Here we can see that the lead of Binance when it comes to BTC holdings is not as big.
Bitfinex comes on the third spot, and with this we are rounding up the big three when it comes to Bitcoin holdings. Bitfinex is often closely associated with Tether USDT.
In a recent period the BTC balance on exchanges has been going down a lot. From more than 3M to around 2M where it is now. More in a longer post :)