Cryptocurrency exchange operators Coinbase and Bitfinex have been experiencing technical problems in the two seemingly unrelated incidents.

Coinbase’s website, as of 17:00 GMT Tuesday, showed “service unavailable,” flashing a message that said it was down for maintenance. Its exchange, the gdax.com, appeared to be operational, stating, however, that it was experiencing “minor service outage.”

Transactions in litecoin and ethereum have been suspended, displaying a “major outage” message. The outage coincided with the litecoin reaching a new height, with the currency showing an astounding 6,000 percent growth this year. It remained unclear whether the outage was related to the “maintenance” itself, overflow of eager cryptocurrency traders or a cyberattack.

Another major exchange, Bitfinex, has reported a large distributed denial of service (DDoS) with its webapps being out. The exchange has been also experiencing a large-scale DDoS attack on its services last week.