Altcoins were in rally mode this week after lagging bitcoin in its recent climb to new 2023 highs. While bitcoin touched an 18-month high and ether broke through the key psychological level of $2,000 for the first time since April, the real spikes were in the rest of the crypto market. Solana notched a 40% weekly gain, Polygon’s MATIC token gained 25% and Cardano’s ADA advanced 17%. Bitcoin and ether rose 8% and 15%, respectively, for the week. “The crypto space has largely been a one-man show over the past year. Bitcoin has led the charge to the upside, while ETH and altcoins couldn’t catch a bid,” said Rob Ginsberg, an analyst at Wolfe Research. “That is no longer the case as altcoins across the board woke up and joined in bitcoin’s rally over the past two weeks.” Now, traders are keeping an eye on whether the gains hold, or if this is just a brief risk-on moment. “Many [altcoins] are deeply overbought and a part of concerning longer term trends, but the drastic improvement certainly can’t go ignored,” Ginsberg added. “Many of the moves are in the ballpark of parabolic, so we’ll be watching to see if a more meaningful regime change is at hand or if they succumb to overbought conditions.” It’s not exactly clear why altcoins had such a great week, but between bitcoin’s recent break above $30,000 and the 10-year U.S. Treasury yield falling to start November – after touching a 16-year high in late October – it’s not exactly surprising. High yields tend to put pressure on crypto , as with any other risk asset. Bitcoin and ether have been separate from this trend recently, with more investors appearing to treat them as a safety trade compared to smaller, riskier altcoins. It’s also normal when bitcoin rallies to see a period of ether and altcoins play catch-up, according to Ryan Rasmussen, analyst at Bitwise Asset Management. “Historically we’ve seen bitcoin rally, then Ethereum, then alts, and that pattern seems to be repeating as this bull market heats up,” he said. The next step for bitcoin The leader of the crypto market has been climbing on growing optimism about a potential bitcoin ETF approval, but it remains to be seen if that can sustain the new high in its price between now and then – or how altcoins would follow. Investors seem to agree ETF approval could come in the first half of 2024, although some like Galaxy Digital CEO Mike Novogratz think it could be as soon as this year . JPMorgan’s Nikolaos Panigirtzoglou said the current ETF-fueled rally “seems rather overdone.” “We see as a more likely scenario existing capital shifting from existing bitcoin products such as the Grayscale bitcoin trust, bitcoin futures ETFs and publicly listed bitcoin mining companies, into the newly-approved spot bitcoin ETFs,” he said. He also said that bitcoin ETFs already exist in Canada and Europe but haven’t garnered much interest from investors since their inception. JPMorgan is “cautious on crypto markets going forward with a high chance of ‘buy the rumor, sell the fact” effect post the forthcoming SEC approval of spot bitcoin ETFs,” Panigirtzoglou said. Additionally, he touched on the upcoming Bitcoin halving, expected in spring 2024, which is designed to reduce the supply of the cryptocurrency and historically marks the beginning of the next big bull run in crypto. “This argument seems unconvincing as the bitcoin halving event and its effect are predictable and in our opinion are well factored into bitcoin price,” he said. —CNBC’s Michael Bloom contributed reporting.