Altcoin Momentum Builds as BTC Dominance Falls and Open Interest Surpasses Bitcoin

Is the market showing the strongest altcoin rally sign yet in 2026?

At a technical level, Bitcoin dominance has opened September lower, having been rejected at the important 60% level. At the same time, the total market cap of altcoins outside the top 10 crypto assets has seen a more than 10% increase from the month’s start.

As the chart below shows, the TOTAL ex-top 10 market cap has broken above the $200 billion level and is clearing the mid-May resistance zone. In effect, it is a capital rotation scenario, with BTC shedding dominance and smaller coins gaining, which could be an early sign that the much-anticipated altcoin cycle is finally getting underway.

Given these circumstances, it may be worth considering shorting Bitcoin [BTC].

Interestingly, a whale has just opened up a $50 million BTC short with 13x leverage. With BTC trading around the $80,000 resistance zone and dominance weakening, the position suggests that some big players might be taking a BTC profit while inflows are made in altcoins.

That said, the leverage buildup isn’t sparing altcoins. If this trend holds, the rally could become crowded and vulnerable to a quick flush. Thus, even though the conditions are right for an altcoin rotation, increased leverage may very well dictate whether this will be a beginning of a new cycle or just another short-lived rally.

Altcoin Open Interest (OI) is now higher than Bitcoin open interest for the first time since December 2024.

Back then, BTC climbed to a record-breaking level near $108,000, while the total crypto market cap climbed to around $3.91 trillion. However, such a rapid rise was accompanied by a significant expansion of leveraged positions. Thus, on the 9th of December, the market saw over $1.5 billion in liquidations, with roughly $1.38 billion coming from long positions.

The main point is a rapid unwind of leverage across altcoins. Altcoin open interest relative to market cap increased from 3.57% to 4.42% before cascading liquidations sent the figure back down to 3.96%. The move wiped out over $12.8 billion in altcoin OI, marking the biggest drop in history at the time. In this context, the current setup naturally deserves due caution.

Altcoin OI overtaking Bitcoin’s shows that traders are turning more aggressive on the space, but also that leverage is accumulating at a rapid rate. If this trend reverses before spot demand is able to absorb it, the market could see a large liquidation event.

This setup becomes more compelling as the overall altcoin market cap outside the top 10 approaches the critical $220-$230 billion rejection zone. Given that BTC dominance is declining and Bitcoin’s own $80,000 appears to be an obstacle, this setup could set off a short-altcoin rally. However, for the broader altcoin cycle, the overall market cap needs to overcome this obstacle first.

Otherwise, the altcoin rally can quickly lose steam in case the level cannot hold its value once again. Meanwhile, with leveraged longs already in place, a failed breakout followed by a bearish move can trigger a broad market selloff, making this a key trend to keep an eye on.