Cryptocurrencies snapped an almost weeklong run above resistance levels as a strengthening dollar sent global equity and currency markets into declines.

Ether (ETH) and Cardano's ADA have both dropped almost 9% in the past 24 hours, giving up a week's worth of gains to become the biggest decliners among major cryptocurrencies. Ether's slide came despite the activation of the Bellatrix upgrade – the Ethereum network's final "hard fork" before the Merge – on Tuesday.

Bitcoin (BTC) fell 5.5%, trading under $18,900 in early European hours. BNB and Solana’s SOL fell 5%; XRP dropped 4% and Polkadot’s DOT lost 7%. Futures tracking major tokens racked up $327 million in liquidations, while the total cryptocurrency market capitalization slid below $1 trillion for the first time since July.

Losses on meme coins dogecoin (DOGE) and shiba inu (SHIB) averaged 6%. Outside of the majors, Ethereum Classic’s ETC fell some 16% after a double-digit rally on Tuesday, with Terra’s old luna classic (LUNC) tokens seeing a 20% slide after more than doubling over the past week.

Concerns about aggressive U.S. Federal Reserve monetary tightening were heightened when the dollar climbed overnight, hitting a 24-year high against the Japanese yen and setting a lifetime peak against the Indian rupee. The S&P 500 lost 0.4% and the Nasdaq 100 0.7% on Tuesday as tech stocks slid.

In a note Wednesday, analysts at Arcane Research warned of increased volatility in the coming days after the U.S. Consumer Price Index (CPI) data for August is released on Sept. 13. Also, the European Central Bank will make its interest rate decision on Thursday. The ECB is forecast to hike rates by 75 basis points. One basis point is a hundredth of a percentage point.

“These macro events, combined with the Merge, might be catalysts for going forward,” the analysts said, adding traders remained bullish on ether ahead of the Ethereum blockchain's Merge event.

As for bitcoin, the Fed’s expected tightening presented a “bad outlook,” according to Chris Esparza, founder of decentralized finance (DeFi) protocol Vault Finance.

“Tightening generally reduces the printing of cash to prop up the economy as we had in the COVID-19 pandemic years,” Esparza said. Bitcoin investors must focus on the fundamentals of the asset instead of relying on macroeconomic market gauges, he told CoinDesk.

“With countries formulating functional regulations to guide the nascent ecosystem, the level of adoption is bound to grow in the long term, creating a positive stance for investors to stack up now."