Bitcoin (BTC-USD) marched higher in Friday morning trading, briefly exceeding the $30K mark at one point, as cryptocurrency investors grew more optimistic that a spot bitcoin exchange-traded fund will soon be approved.

The most popular digital token (BTC-USD) gapped up 3.1% to $29.6K at 10:49 a.m. ET. It's on track to close out the week with an over 10% gain. Ethereum (ETH-USD), the world's largest altcoin by market cap, advanced 3.2% to $1.61K and is on pace for a nearly 5% weekly rise.

Earlier on Friday, Paul Grewal, chief legal officer at Coinbase (COIN), reportedly said he's "hopeful" that a spot bitcoin (BTC-USD) ETF will soon be greenlit by the U.S. Securities and Exchange Commission. He didn't say exactly when he thought that might happen. Any decision, of course, remains up to the SEC, he added.

For a more specific projection, Galaxy Digital (OTCPK:BRPHF) CEO Michael Novogratz has said an ETF that invests directly in bitcoin (BTC-USD) will get approved as soon as this year. Barclays analyst Benjamin Budish, meantime, has contended that bitcoin (BTC-USD) ETF approvals would start to take effect next year, with the timeline of approval for the ARK 21Shares Bitcoin Futures Strategy ETF (ARKA) closest to expiring.

A spot BTC ETF, designed to track the price of bitcoin (BTC-USD) rather than bitcoin futures prices, is fitted for those who want to be directly exposed to bitcoin without actually owning the underlying token.

The spot ETF excitement was also reflected across crypto-linked stocks, with Hut 8 Mining (HUT) +10.1%, Core Scientific (OTCPK:CORZQ) +11.3%, CleanSpark (CLSK) +8.7%, MicroStrategy (MSTR) +3.2% and Riot Platforms (RIOT) +5.1% among some of the biggest gainers.