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Fidelity Digital Assets says fears about Bitcoin’s long-term security are overstated, even as block rewards continue to decline with each halving. In the first of a two-part report published in June 2026, senior research analyst Daniel Gray examines historical miner revenue, attack scenarios, and price models to argue that the network’s security remains durable.
The analysis arrives with Bitcoin trading near $60,000 and as discussions around quantum risks and the next halving keep the topic in focus. Fidelity’s report focuses on proof-of-work economics rather than quantum threats, but its timing gives it added relevance in the current market environment.
The most striking data point in Fidelity’s report is rarely mentioned in security budget discussions. According to the report, while bitcoin-denominated block rewards have declined by roughly 94% since 2009 due to successive halvings, USD-denominated miner revenue has risen by 157,836% over the same period.
Price appreciation has consistently absorbed the reduction in coin issuance. Fidelity models the bitcoin price levels needed to sustain current miner economics through future halvings, assuming stable hash rate, difficulty, and transaction fees. These required prices are closely aligned with established quantile regression models that track Bitcoin’s long-term trajectory relative to its trend.
We've been in one of the most notable hashrate bear markets since the 'oct bitcoin peak. Other than radical repricing to the upside, I'm not sure what arrests this fall considering it's simply more economical to now mine AI.
There's a few underpriced hedges to this at least https://t.co/bor6beM5dJ pic.twitter.com/iUsmBTgdOf
— Tulip King 🌷 (@tulipking) June 30, 2026
The implication is that if Bitcoin continues appreciating along its historical path, miner incentives can remain viable without depending entirely on transaction fees to fill the gap. Fidelity acknowledges uncertainty around fee growth, but argues that critics have often overstated the security budget risk by looking only at the declining coin-denominated reward.
The report reveals that since the 2016 halving, Bitcoin’s hash rate has surged more than 8,000%. Since the 2020 halving, it has climbed 394%. Both periods included halvings that cut miner rewards in half. When hash rate grows through a halving instead of contracting, it is the clearest available signal that miners remain economically motivated to secure the network despite declining issuance.
Bitcoin’s difficulty adjusts every 2,016 blocks (about every two weeks), lowering mining difficulty if miners exit after a halving to restore profitability and maintain network security.
Fidelity says 51% attacks are economically impractical at Bitcoin’s current scale. Double-spend and censorship attacks become increasingly difficult and costly to sustain as the network adapts and honest miners are incentivized to participate.
Bitcoin has a hidden feature that’s kept it flawless for 17 years: automatic difficulty adjustment.
Every 2,016 blocks (~2 weeks), the network recalibrates. Too fast? Harder math. Too slow? Easier. Target: one block every 10 minutes, always.
In 2021, China banned mining—half…
— Jeff Swanson (@theswansjr) June 26, 2026
The next halving, expected around 2028, will cut block rewards from 3.125 BTC to 1.5625 BTC. That event will serve as another practical test of whether price appreciation, transaction fees, and miner economics can sustain network security without major disruption.
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