Investor sentiment toward cryptocurrencies surged this week, with growing retail interest in altcoins suggesting Bitcoin’s recent euphoria phase may be nearing an end, according to analysts.

The crypto asset sentiment index rose from 0.23 to 0.91 within a week, according to Max Shannon, senior research associate at crypto index fund manager Bitwise.

Google searches for altcoins and Ethereum also rose to a multiyear high, reminiscent of prior bear markets, which may signal a growing investor mindshare for altcoins and Ether (ETH), following Bitcoin’s latest all-time high above $124,000.

These developments mark a “classic froth-infused behaviour that can precede buyer exhaustion,” said Shannon in a Thursday X post.

Buyer exhaustion occurs when diminishing buy orders are overwhelmed by selling pressure, potentially leading to a Bitcoin (BTC) pullback as capital rotates into other cryptocurrencies.

Bitcoin dipped below $118,000 on Thursday as investors digested comments from US Treasury Secretary Scott Bessent, who said the government had no plans to make additional purchases for its Strategic Bitcoin Reserve and separate digital asset stockpile.

Bessent backpedalled on his statement hours later, clarifying that his department was still exploring budget-neutral ways to acquire BTC for the Strategic Bitcoin Reserve.

“Treasury is committed to exploring budget-neutral pathways to acquire more Bitcoin to expand the reserve, and to execute on the President’s promise to make the United States the ‘Bitcoin superpower of the world,’” Bessent wrote in an X post on Thursday. 

The Crypto Fear & Greed Index shifted from “greed” to “neutral” territory, falling to 59 at the time of writing, down from 68 on Thursday, CoinMarketCap data showed.

Despite the drop into neutral territory, investor sentiment remained “elevated but shy of euphoria, leaving room for trend continuation if macro doesn’t deteriorate,” according to Stella Zlatareva, dispatch editor at digital asset investment platform Nexo.

Favorable policy developments, such as the Securities and Exchange Commission’s incoming Solana exchange-traded fund (ETF) decision deadline in October, signal that the “uptrend’s broader narrative remains intact,” she told Cointelegraph. 

Related: Bitcoin briefly flips Google market cap as investors eye rally above $124K

Buyer exhaustion may precede the September altcoin rally

While a wider crypto market correction may still occur during the lack of investor activity characteristic of August, many industry watchers are expecting an altcoin rally in September.

“We think current market conditions now suggest a potential shift towards a full-scale altcoin season as we approach September,” Coinbase Institutional’s global head of research, David Duong, wrote in a monthly outlook report on Thursday.

Altcoin season implies that at least 75% of the 50 largest altcoins by market capitalization outperform Bitcoin’s price over the previous 90 days.

Related: Bitcoin’s corporate boom raises ‘Fort Knox’ nationalization concerns

The altcoin season index climbed from 33 to 42 during the past week, but remained below the 75 level, which signals the beginning of the altcoin season, CoinMarketCap data showed.

Bitcoin and Ether prices stabilizing may “provide a great window for the first serious leg upwards for altcoins,” according to MN Trading Capital founder Michaël van de Poppe.

“They are primed to start running, just like Ethereum did. What’s the upside? Probably like 100-150% in the first run,” the analyst said in a Friday X post.

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