Crypto exchanges have become the most powerful stakeholders in the crypto ecosystem. Currently, just 12 crypto exchanges hold around 2.5 million Bitcoin (BTC) in their wallets, worth around $15 billion. That’s 13.8% of all Bitcoin mined to date — or, 16%–17% of all Bitcoin in circulation, considering lost Bitcoin (as of March 19).
Exchanges are also some of the largest holders of altcoins, which recently led to a controversy when some of the biggest crypto exchanges used large stockpiles of Steem tokens to take over Steemit.