Bitcoin’s price continued to decline on Friday, ending the week down about 2% compared to a 1.7% gain in the ether cryptocurrency. Some traders who went long on BTC ahead of the launch of ProShares’ futures-focused exchange-traded fund (ETF) this week appear to be taking profits.

Still, some investors expect pullbacks to remain limited for the remainder of the year. And one firm mentioned that alternative cryptocurrencies such as ether could see further upside relative to bitcoin.

“We remain optimistic but are cautious about downside risk,” crypto trading firm QCP Capital wrote in a Telegram announcement. The firm noted that leverage levels are high in the bitcoin futures market, which typically precedes a price pullback. QCP also expects ether to outperform bitcoin in the near term.

Valkyrie Investments’ Bitcoin Strategy ETF, another futures-focused product, went live on the Nasdaq under the ticker BTF on Friday. The ETF’s share price tracked bitcoin lower during its first day of trading, down about 4% and closing at $24.30.

The amount of money locked in the CME-based futures contracts has tripled this month, with more than $1.5 billion flowing into the market after the ProShares Bitcoin Strategy ETF (NYSE: BITO) went live on Tuesday, reported CoinDesk’s Omkar Godbole.

However, BITO could be exposed to a significant tracking error, or the difference between bitcoin’s performance and actual returns from the fund.

This is because the CME allows a single entity to own a maximum of 2,000 contracts in the front-month futures while capping the overall positions across different maturities at 5,000 contracts. BITO appears to be close to hitting the limit in the October expiry and may continue to snap up longer duration futures, according to Godbole.

Ether, the world’s second-largest cryptocurrency by market capitalization, slipped below the $4,000 price level on Friday. Similar to bitcoin, technical indicators show ether is at its most overbought point since September, which preceded a sharp price pullback. This time, however, ETH’s pullback could be limited to around the $3,700 support level.

The ETH/BTC ratio stabilized over the past week, suggesting that traders are beginning to rotate out of BTC and into ETH. The ratio held support around 0.06 and could face short-term resistance around 0.07 and 0.08.

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

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

Notable losers: