US spot Bitcoin ETFs recorded net outflows of $158.3 million on Dec. 20, with IBIT alone accounting for $173.6 million in redemptions, FarsideInvestors data show. US spot Ethereum ETFs posted $75.9 million in net outflows over the same period, all from BlackRock's ETHA.

Castle Island Ventures co-founder Nic Carter said on Dec. 20 that quantum computing is only an "extremely difficult" engineering challenge away from breaking Bitcoin and would not require new discoveries in fundamental physics, BlockBeats reports. He wrote that Bitcoin could adopt post-quantum signature schemes through a soft fork, but key obstacles include choosing a specific scheme, coordinating the fork process, and migrating balances across tens of millions of addresses. Carter warned that mitigation may take nearly ten years and that 1.7 million BTC in abandoned addresses could face sudden theft even after a post-quantum upgrade unless holders collectively agree to seize those coins, a step he described as unprecedented in Bitcoin's history.

Macro analyst Luke Gromen, founder of Forest for the Trees, said on Dec. 20 in podcast "The Monetary Matters Network" that he has shifted to a short-term bearish view on Bitcoin despite holding a long-term bullish position and accumulating most of his holdings below $30,000 in late 2022 and early 2023 without selling. Gromen cited Bitcoin's strong correlation with tech stocks, the prospect that future AI competition will be constrained by electricity rather than semiconductors, Bitcoin's lack of breakout versus gold under a liquidity outlook of "nuclear-level money printing or tightening," and potential threats from quantum computing that "could become an issue in 2 to 9 years." He also pointed to Tether's recent moves into AI and gold, noting that its balance sheet holds more gold than Bitcoin, as factors worth monitoring.

BlackRock's spot Bitcoin ETF IBIT recorded a -9.59% return, making it the only fund with a negative performance among the top 25 U.S. ETFs by annual inflows, Eric Balchunas reported on X on Dec. 20. IBIT's yearly inflows ranked sixth, surpassing GLD, which posted a 64% return.

Arthur Hayes said in his Dec. 20 article "Love Language" that the Federal Reserve's RMP is effectively a new QE, and he expects Bitcoin to trade in the $80,000–$100,000 range in the short term, BlockBeats reports. He added that once markets recognize "RRP = QE", Bitcoin could revisit $124,000 and test $200,000, with a sentiment peak around next March and a floor above $124,000. He also moved 508.647 ETH ($1.5 million) to Galaxy Digital yesterday amid a rebound, which may have been to sell, BlockBeats said.

Citigroup set a 12-month base case of $143,000 for Bitcoin on Dec. 20, 62% above $88,000, BlockBeats reports. The bank's joint report identified $70,000 as key support, citing ETF demand recovery. Scenarios range from $78,500 in a recession to $189,000 under stronger demand, according to the report.

Bitcoin demand growth has slowed markedly since early October 2025, potentially signaling a bear market, CryptoQuant said in a December 20 report. The firm identified three major spot-demand waves since 2023 tied to U.S. spot ETF launches, the U.S. presidential election, and a bubble among Bitcoin treasury companies, noting demand has remained below trend since early October and suggesting most incremental demand in the current cycle has been realized. In derivatives, the 365-day moving average of perpetual futures funding rates dropped to its lowest since December 2023, reflecting reduced willingness to maintain long positions, a pattern CryptoQuant said typically occurs in bear markets. Technically, Bitcoin has fallen below its 365-day moving average, with historical markers placing bear-market bottoms near the realized price of around $56,000, implying a potential 55% drawdown from recent highs, which would be the smallest ever, and mid-term support expected near $70,000.

Sean Farrell, head of digital asset strategy at Fundstrat, said in a Dec. 20 report he expects a notable downside move in the first half of 2026, with Bitcoin potentially falling to $60,000-$65,000 and Ethereum to $1,800-$2,000, while SOL could retrace to $50-$75. Farrell set a year-end 2026 target of about $115,000 for Bitcoin and suggested Ethereum could reach around $4,500. He noted that under this framework ETH may show relative strength due to more favorable structural flows, including the lack of miner selling pressure, no impact from MSTR-related factors, and comparatively lower concerns about quantum risk.