Coinbase Global (NASDAQ:COIN) shares are perking up as much as 15% in Friday premarket trading, as bitcoin (BTC-USD) and other major cryptocurrencies experience some relief after heavy selling pressure took hold since the beginning of May. Bitcoin (BTC-USD +7.8%) has rebounded back over $30K, changing hands at $30.7K as of shortly before 9:00 a.m. ET. Ethereum (ETH-USD +8.0%) is up and over its psychological key level of $2K as well, standing at $2.12K. Overall, bitcoin (BTC-USD) has still wiped out gains over the past year, but large drawdowns aren't anything new in the crypto ecosystem, Coinbase (COIN) CFO Alesia Haas told CNBC's Squawk Box Thursday evening. "We've navigated through crypto cycles," she said, adding that bitcoin had already experienced a series of severe selloffs in the past, including an 80% drop from 2017 to 2018, "and we've always come out stronger." As for other crypto-related stocks, Silvergate Capital (SI) +11.3%, MicroStrategy (MSTR) +15.7%, Bakkt (BKKT) +4..7%,