Bond Jitters & a Bitget Breach

Bitcoin traded at $84,181 on September 25, 2026, down 0.23% from its latest daily close and 33.27% below its all-time high. Its September 2026 performance remains ahead of the month’s usual seasonal pattern so far, but that is not a complete result: Bitcoin has begun pulling back during the late-September window that has historically tended to improve. 

At $84,181, Bitcoin is up $6,986, or 9.05%, from its $77,195 price on September 1, when the Fear & Greed Index reached 69, above the historical 21-day median gain of 7.0%, though below the 10.2% average. The decline from $87,200 on September 23 appears more consistent with a bond-volatility shock than a broad deterioration in demand, with ETF buyers continuing to add exposure.

Bitcoin Meets Bond Volatility: Swings Mattered More Than Yields

The US 10-year Treasury yield reached its highest level since 2007 on September 23. The correlation data points to the swing in bond prices, rather than the yield level, as what moved Bitcoin:

• Yields hit a 2007 high: The 10-year jumped 15 basis points on September 23 to above 5.13%, per CoinDesk's analysis.

• The day-to-day link is close to zero: Correlation measures how closely two things move together, on a scale from −1 to 1. A reading of 1 means they move in lockstep, and 0 means no connection at all. CoinDesk puts the reading between Bitcoin and the 10-year yield at −0.18 over 90 days, −0.06 over 180 days and −0.03 over one year. All three sit close to zero, so a move in yields on a given day has told little about where Bitcoin would go.

• Bond turbulence fits the timing better: The MOVE Index, which tracks expected price swings in US Treasuries, rose 21% to 95 on September 23, its highest since April 1. Bitcoin fell from $87,200 to $83,500 in the same session. CoinDesk adds that the market may also have been looking for a reason to pull back after a steep run.

• Leverage took the first hit: Long liquidations reached about $280 million as Bitcoin dipped under $84,000, per Cointelegraph. Forced selling of this kind is the risk Coinjuice examines in why the most profitable crypto traders eventually abandon leverage.

• ETF buyers kept adding: Spot Bitcoin ETFs took in $346.9 million on September 23 and $190.7 million on September 24, per SoSoValue data. That was the sixth consecutive session of net inflows since a $295.9 million outflow on September 16. BlackRock's IBIT accounted for $162.6 million of the September 24 total. Inflows slowed as price fell, but they did not reverse.

• 2026 flows turned positive, on differing counts: On DefiLlama's tracked data, year-to-date net flows moved from about $365.5 million in outflows through September 21 to about $696.1 million in inflows through September 23. Cointelegraph put the year-to-date figure near $596 million. The roughly $100 million gap is unexplained, but both counts agree the funds have moved into net inflows for the year. The September 23 edition had described them as still net negative for 2026.

Coinjuice’s review of eight studies on the Fed and Bitcoin reaches a similar conclusion: Bitcoin responds more to shifts in broader financial conditions than to Treasury yields alone.

Bitget Breach: $351.6M Left Through Its Own Approval System

Crypto exchange Bitget disclosed a breach on September 24. By the company's account, its private keys held but the system that approves their use did not:

• The breach: Bitget's security systems flagged unauthorized transfers from a limited number of hot wallets at 18:31 UTC on September 24, affecting about $351.6 million in assets, per Cointelegraph. Withdrawals were paused; deposits and trading continued.

• The method, per the exchange: CEO Gracy Chen said attackers compromised a critical backend system in the wallet infrastructure, spoofed transaction data and triggered Bitget's own authorization process. "Private key compromise has been ruled out," she wrote, per CoinDesk.

• Attribution is preliminary: Chen said investigators identified IP addresses matching VPN services previously used by a North Korean hacking group, per CNBC. She described the findings as preliminary. The attackers' identity has not been confirmed.

• Hot, warm and cold layers: Hot wallets stay online to process withdrawals quickly. Warm wallets sit between them and offline storage, topping them up as needed. Bitget said the breach reached parts of both online layers, while its cold wallets remained secure.

• Coverage is the exchange's stated position: Bitget says its User Protection Fund holds more than $464 million and covers the full loss, and that account balances remain accurate. These are company statements; no independent verification of the fund's balance was located.

• What is still open: Chen said investigators are still working out how the attackers gained access, and a full technical report will follow. Bitget has not given a timeline for restoring withdrawals.

On Bitget's account, the attackers never needed the keys. They needed the machinery that tells the keys when to sign. The incident is an exchange infrastructure failure, not evidence of a flaw in Bitcoin or any other underlying asset. It still narrows the lesson for anyone holding coins on a platform: those coins depend on the platform's software and approval process as well as its key storage.

Quantum-Safe Bitcoin: An Emergency Exit Gets 79% Cheaper

A separate development addressed a longer-dated risk to Bitcoin ownership: the possibility that a future quantum computer could derive private keys from exposed public keys.

• What changed: The first quantum-safe Bitcoin (QSB) transaction was mined in August. Preparing it took about 3,100 hours of work on graphics chips, the same kind of processor used for gaming and AI, at a cost of roughly $320. StarkWare, Yukon Research and Eigen Labs then opened the problem to the public as a one-week competition. When the week ended, StarkWare put the estimated cost at about $67 on September 23. CoinDesk reported $66 as the competition's live tracker kept updating.

• How it happened: Preparing a QSB transaction means making billions of guesses until one fits a required pattern, so faster guessing means a cheaper transaction. Competitors, many of them using AI tools to help write code, raised the speed from about 146 million guesses per second to just over 820 million, per StarkWare. That is more than five times faster. CoinDesk later cited a leading entry at about 881 million guesses per second.

• The estimates differ: CoinDesk's own calculation applied the contest's published speedups to the $320 cost breakdown and gave about $83. StarkWare describes its figure as an estimate, not a price. Neither number has been demonstrated in a second mined transaction.

• Why it matters: QSB adds hash-based protection inside Bitcoin's existing rules, so it needs no soft fork. That makes it an emergency option for moving eligible coins if a quantum threat arrives before Bitcoin adopts a broader fix.

• The limits: QSB transactions are nonstandard and must go directly to a miner. The method cannot protect coins whose public keys are already exposed. StarkWare still considers a soft fork the better long-term answer.

In a nutshell: Bitcoin's no-upgrade quantum escape hatch got about five times cheaper in a week, but it still only works for coins that have never exposed their keys.

Coinjuice Lens: Bitcoin Ownership

The September 24 edition looked at the average price ETF buyers paid for their Bitcoin, the level at which they would break even. Bloomberg Intelligence analyst James Seyffart estimated that average at $81,722. An earlier Cointelegraph estimate placed break even levels just below $86,000. 

Later today, Coinjuice will publish an interview with Tether co-founder William Quigley. Quigley argues that Bitcoin and stablecoins are not competing forms of money: Bitcoin is a scarce, volatile asset people hold and trade, while stablecoins are built to move digital dollars.

Readers looking to navigate a market moved by bond volatility and custody risk can start with the Coinjuice ebook, Bitcoin Trading Without Leverage, or go deeper with a Coinjuice subscription, where we start and complete trades and you will learn to snipe them independently.

News Behind Today's Read

• The Data Proves It: Bitcoin Doesn't Care About Rising Bond Yields Over Long-Term (CoinDesk). Source for the 2007-high 10-year yield, the correlation readings, the MOVE Index jump and the $87,200 to $83,500 move.

• Bitcoin ETFs Add $347M as BTC Falls Below $84K After Topping $87K (Cointelegraph). Source for the $2.65 billion five-session total and the externally reported year-to-date flow figure.

• Bitget Confirms $351M Security Breach, Suspends Withdrawals (Cointelegraph). Source for the breach timing, the affected amount, the withdrawal pause and the User Protection Fund figure.

• Bitget's $352 Million Hack Happened via Spoofed Transfers, Not Private Keys (CoinDesk). Source for the attack method as described by Bitget's CEO and the open withdrawal timeline.

• Crypto Platform Bitget Suspects North Korea Is Responsible for $352 Million Hack (CNBC). Source for the preliminary DPRK attribution based on IP and VPN evidence.

• AI Research Competition Cut Quantum-Safe Bitcoin Costs by 79% in a Week (StarkWare). Primary source for the $320 to $67 estimate, the speed gains and the method's stated limits.

• A Week of AI Coding Cut a Quantum-Safe Bitcoin Transaction Estimate From $320 to $66 (CoinDesk). Independent check on StarkWare's figure, including CoinDesk's own $83 calculation.

Continue the read: Sept. 22 · Sept. 21

Market Snapshot

This article was developed with the support of artificial intelligence tools as part of Coinjuice's editorial process and reviewed by our editorial team before publication.

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