What happened
CryptoBriefing reported Tuesday that the Russell 2000 finished the first half of 2025 roughly 14 percentage points ahead of the S&P 500, an unusually wide spread for the two indices over a six-month window. The publication credits crypto-adjacent names inside the small-cap benchmark, specifically listed bitcoin miners, with driving a disproportionate share of that outperformance.
Miners including Marathon Digital, Riot Platforms and CleanSpark sit inside the Russell 2000 rather than the S&P 500 because of their market caps, which means their rallies show up in the small-cap tape rather than in the large-cap headline. When bitcoin's spot price ran and hashprice held up in the first half, those stocks moved harder than the broader small-cap complex around them.
The result is a benchmark spread that reads like a traditional risk-on rotation on the surface but decomposes into something much narrower underneath.
Why it matters
For most of the post-ETF era, the working assumption in traditional allocator meetings has been that crypto exposure lives in the mega-cap sleeve. Spot bitcoin and ether ETFs, Coinbase's S&P 500 inclusion, MicroStrategy's balance sheet trade. Those are the trades TradFi desks talk about.
The H1 2025 spread flips that story. It says that if you owned a plain-vanilla Russell 2000 index fund this year, you were long crypto miners whether you meant to be or not, and that basket carried the benchmark. That has two implications.
It means passive small-cap flows are now a real marginal bid for miner equity, which changes how those companies fund capex and dilution. And it means small-cap benchmark risk has quietly picked up a bitcoin beta that most consultants haven't reflected in their factor models yet.