
Shares of cryptocurrency exchange Coinbase Global COIN.O fall 3% to $255.53 in premarket
Co says it expects to incur between $180 million and $400 million in costs related to a cyber attack
COIN says cyber criminals had stolen account data for a "small subset" of its customers
However, COIN says no passwords, private keys, or funds were exposed and Coinbase Prime accounts are untouched
The company will also not pay the $20 million ransom demand it received
As of last close, COIN has gained nearly 6% YTD