Bitcoin rallied to an all-time high of around $66,000 on Wednesday, reversing a nearly 50% correction earlier this year. Traders remain optimistic and expect further upside across cryptocurrencies as the ProShares Bitcoin Strategy ETF (NYSE: BITO), the first U.S. bitcoin-linked exchange-traded fund, made its debut on Tuesday.

At this point, “short-term corrections outweigh the positive expectations for the final momentum of the BTC rally,” Alex Kuptsikevich, a senior analyst at FxPro, wrote in an email to CoinDesk.

Further upside, however, could be limited if buyers fail to sustain the rally. Kuptsikevich warned that reaching a new high (or a series of highs) may provoke the “beginning of aggressive profit-taking by large investors who opened positions during the rebound from $30K.”

For now, in the bitcoin options market, traders are pricing in expectations for larger price moves.

“Implied volatility is creeping higher after spiking last week around the bitcoin ETF approval,” Gregoire Magadini, CEO of Genesis Volatility, wrote in an email to CoinDesk.

“The theme of $100K BTC by end-of-year is back in vogue,” Magadini wrote.

BTC could continue higher as bullish momentum improves, price-chart indicators suggest.

A successful breakout would require a daily close above $65,000, which would yield upside targets toward $74,000 and $86,000. BTC will need to see continued buying pressure to keep the current rally intact, preferably above $60,000-$65,000. Read more here.

Blockchain indicators also point to further upside for bitcoin. For example, BTC’s market-value-to-realized-value (MVRV) ratio suggests that the price is not yet overvalued.

“Throughout the 2013, 2017 and 2021 runs, an MVRV of 3.0 or above has indicated a local price top,” crypto research firm Coin Metrics wrote in a Tuesday newsletter. “At the other end of the spectrum, an MVRV of 1.0 or below has signaled the bottom of a cycle,” the firm wrote.

MVRV recently broke above the 2.0 level for the first time since May, which also occurred during the start of bitcoin’s 2020 bull run.

Market participants are increasingly bullish as cryptocurrencies gain greater traction among global investors.

While futures-based ETFs are not investors’ first choice, the combination of crypto and ETFs could make a big splash by introducing a new class of investor to both sectors. Consider that the global ETF industry has $9.4 trillion in assets under management, growing at an annual rate of 26%, while crypto’s market capitalization sits at $2.75 trillion, CoinDesk’s Edward Oosterbaan and George Kaloudis wrote.

If the first day of trading was any indication, the U.S. market has clearly been waiting for easier access to bitcoin. Read more here.

Most digital assets in the CoinDesk 20 ended the day higher.

Notable winners as of 21:00 UTC (4:00 p.m. ET):

Notable losers: