Gold Finance reports that on Oct. 5 the U.S. Securities and Exchange Commission approved Cboe BZX Exchange rule changes that clear the way for Volatility Shares LLC to list a 3x Bitcoin Futures ETF along with five other leveraged commodity products. The lineup also includes a 3x Ethereum ETF and leveraged exposure to gold, silver, crude oil, and natural gas. The 3x Bitcoin strategy is designed to deliver three times the daily return of its futures benchmark before fees: a 1% move in the benchmark implies a targeted 3% gain, while a 1% decline implies a targeted 3% loss. The funds seek exposure via futures contracts rather than holding Bitcoin directly, and daily compounding can cause longer-term results to diverge from the benchmark's cumulative price change. Trading can begin once each registration statement becomes effective. Each product must have at least 100,000 shares issued at the open, and net asset value per share will be calculated daily.

BlackRock has purchased roughly $1.6 billion worth of Bitcoin so far this month. Over the past month, the firm has net accumulated around $1.57 billion in $BTC, according to @Arkham data. On Friday alone, it added nearly $200 million in $BTC, a move seen as likely tied to ETF-related flows.

Bitcoin Core has introduced a new safeguard to stop wallets and signers from producing signatures that may fail to lock funds to the recipient a user approved. The change was merged into Bitcoin Core's master development branch on Sept. 25 and was highlighted by Bitcoin Optech on Oct. 2. The issue sits in a narrow corner of partially signed Bitcoin transactions (PSBTs). It does not reveal private keys. Instead, it can create a scenario where a signature remains valid even if the transaction's recipient is altered under specific conditions, creating an authorization gap for users. At the center is SIGHASH_SINGLE, a signing mode intended to bind an input to the output at the same index. If the transaction lacks an output at that position, the protection can fail in different ways depending on the input type. For legacy inputs, the "missing output" condition can lead to a signature over a fixed hash value. Bitcoin Core developers said such a signature could potentially be reused against other unspent outputs controlled by the same key when the same structural conditions exist. SegWit v0 inputs are more constrained because the signature still commits to the specific coin being spent and its amount. Even so, the destination output can remain unbound, meaning software could show one payment destination to a user while generating a signature that does not cryptographically guarantee the approved recipient stays unchanged. Bitcoin Core previously rejected this edge case through its rawtransaction signing interface, but PSBT workflows could still sign it, including via walletprocesspsbt. The new patch moves the check into shared signature-creation logic. That prevents signing affected legacy and SegWit v0 inputs while still allowing other valid inputs in the same PSBT to proceed. PSBTs are widely used to coordinate transactions between software wallets, hardware devices, and offline signers, enabling transaction construction and signing without exposing private keys. The update reinforces a different boundary: signatures should commit to the transaction details the user actually authorized. Bitcoin Improvement Proposal (BIP) 174, which defines PSBTs, already advises signers to reject unacceptable signing modes and recommends SIGHASH_ALL when no alternative is specified. Bitcoin Core's change ensures this missing-output configuration is blocked before it reaches the signing stage. A production release containing the safeguard has not yet been confirmed. The patch landed in the development branch on Sept. 25, and as of Oct. 4, Bitcoin Core's release listings had not identified a fixed version or confirmed a backport. In the meantime, wallet providers and hardware-signing integrations face a near-term decision: audit and tighten their own handling of SIGHASH_SINGLE requests rather than waiting for a downstream Bitcoin Core release to enforce the same protection. The original report appeared on CryptoSlate.

The U.S. Securities and Exchange Commission has approved Cboe BZX Exchange rule changes allowing Volatility Shares LLC to list a 3x Bitcoin futures ETF along with five additional leveraged commodity products, according to Odaily Planet Daily. The lineup also includes a 3x Ethereum ETF and leveraged exposure tied to gold, silver, crude oil, and natural gas. Volatility Shares' Bitcoin strategy is designed to deliver three times the daily performance of its futures benchmark before fees: a 1% move in the benchmark targets a 3% move in the ETF in the same direction. The funds will gain exposure through futures contracts rather than holding Bitcoin directly. The disclosure notes that daily compounding can cause returns over longer periods to diverge from the benchmark's cumulative price change. Trading can begin once each product's registration statement becomes effective. At launch, at least 100,000 shares must be issued for each product, and net asset value per share will be calculated daily. (Bitcoin.com News)

A total of 4,500 BTC, valued at $383,961,630, was transferred from an unidentified wallet to a newly created, unidentified wallet.

Bitcoin got off to a positive start for "Uptober", supported by fresh demand through U.S.-listed spot Bitcoin ETFs. The group attracted a combined $134 million in net inflows, extending signs of renewed investor appetite at the start of October.

JUST IN: Michael Saylor is hinting that Strategy could add to its Bitcoin holdings again this week, posting "More orange than ever." The tease comes after two straight weekly Bitcoin purchases in September. Strategy currently holds 847,666 $BTC.

ChainCatcher reports that Michael Saylor's latest post on X, featuring a chart of Strategy's historical Bitcoin purchases and the caption "More orange than ever," is widely seen by markets as a hint that the company may soon disclose another BTC acquisition. According to the chart, Strategy holds 847,666 Bitcoin in total, purchased at an average cost of about $75,400 per coin, valuing the position at roughly $72.29 billion.