Key Takeaways
Are we in a full-blown altcoin season?
Altcoins are rallying hard, but market froth is missing, creating a divergence from past seasons.
Are altcoins at risk?
The rally is driven by speculative flows, leaving altcoins exposed to post-FOMC swings.
September has officially turned into “altcoin season.” Billions have poured into the space, pushing TOTAL3 (market cap ex-BTC/ETH) to a record $1.16 trillion, now representing roughly 28% of the total crypto market.
The Altcoin Season Index has reacted sharply. It surged to a cycle high of 80, meaning 40 out of the top 50 altcoins outperformed Bitcoin [BTC] over the last 90 days, with Pudgy Penguins [PENGU] leading the pack.
And yet, the froth is missing. The Fear and Greed Index is showing no euphoria, marking a clear divergence from previous alt rallies.
Simply put, traders could be reading a “pump-and-dump” cycle as an alt season.
Source: CoinMarketCap
Historically, alt rallies were accompanied by frothy sentiment.
During the last alt seasons (January and December 2024), Fear and Greed hit “extreme greed” as the Altcoin Season Index pushed close to 85. Back then, speculative rotation and market euphoria were running in sync.
The SOL/BTC ratio backed this up, topping around 0.03 and chopping in that range all year. Now, the ratio is nearly 30% lower, even with a full-blown “alt season,” signaling rotation without the usual market froth.
Altcoin Open Interest (OI) has reached new all-time highs.
At press time, total altcoin OI surged to $38.9 billion, surpassing Ethereum’s $29.4 billion and approaching Bitcoin’s $40.5 billion.
This signals heavy market positioning and a buildup of leverage ahead of the upcoming FOMC meeting.
Solana [SOL] is leading the charge, with $7.6 billion in OI, representing 19.5% of total altcoin OI.
Additionally, the SOL/BTC ratio has climbed 8.77%, indicating that this momentum is likely driven by rotation flows into Solana.
Source: Coinalyze
However, as AMBCrypto noted, euphoria still isn’t here.
Leverage is ramping up, speculative capital is flowing into alts, yet overall rational flows are still tame compared to past cycles. Dogecoin [DOGE] reflects a similar pattern.
The DOGE/BTC ratio was up just 17%, as of writing, far below the 60%–90% monthly surges seen during past alt seasons.
This suggests the current rally is primarily speculative, leaving altcoins vulnerable to sharp price swings following the upcoming FOMC decision.
