Arbitrum Halts New Stylus Activations Over AI Attack Risks
Arbitrum (ARB)
Editor:
Eugene Serbin
cvj.ai reports that Arbitrum’s Security Council paused new Stylus contract activations on October 2 to mitigate AI-assisted threats. The emergency measure blocks fresh activations on both Arbitrum One and Arbitrum Nova, though existing applications and standard Solidity contracts remain unaffected. This pause specifically targets the activation step required to make WebAssembly programs executable, while deployment continues normally.
The Council cited sophisticated attacks using hand-crafted WebAssembly programs outside the standard toolchain that exploit bugs threatening chain liveness. No theft of user funds has been detected, but the risk to network availability prompted the swift action. The restriction was implemented by raising the activation gas requirement to a prohibitively expensive level without requiring an ArbOS upgrade.
Developers can still extend active programs via keepalive renewal, but reactivating expired programs is now blocked. A separate safeguard was also installed for BoLD’s one-step proofs on Arbitrum One to pause settlement to Ethereum if conflicting answers arise. This ensures conflicts are resolved before finalizing transactions, adding a layer of security to cross-chain communications. The Council provided no date for restoring activations, stating the Arbitrum Foundation will coordinate with ArbitrumDAO on the timeline.
How the market reacted
Whalio's own Binance spot order flow for ARB, measured when this story was written up on 3 October 2026. Not the outlet's figures.
ARB trades at $0.1959 with a 1-hour buy ratio of 44.5%, indicating a short-term imbalance where sellers are currently outpacing buyers. This contrasts with the 4-hour buy ratio of 51.2%, suggesting that buying pressure has built up over a slightly longer timeframe. The 24-hour buy ratio sits at 49.4%, showing a near-even split in trading activity over the full day. Volume Delta reflects this dynamic, with a negative $21,253 in the last hour versus a positive $54,253 over four hours. Volume Delta measures the net difference between buy and sell volume; a negative figure means more money flowed into sells than buys. The 24-hour Volume Delta is -$193,604, confirming that net selling pressure has dominated the day despite the recent four-hour shift toward buying.
The latest daily buy ratio of 49.6% sits at the 49th percentile of the last 322 days, against a median of 49.6% - ordinary for this coin.
Was that an ordinary day?
The same Binance spot measurements for ARB, averaged over the days leading up to the story.
Over the preceding week, ARB experienced a 13.6% price decline and a total Volume Delta of -$3,018,353. The 24-hour spot volume of $18,805,801 is significantly lower than the weekly average, trading at just 0.71x normal levels. This indicates that today’s activity is subdued compared to the typical trading volume seen over the last seven days. While the 24-hour buy ratio of 49.4% is slightly above the weekly average of 49.2%, the volume contraction suggests reduced interest. Only one of the past seven days saw net buying, highlighting that selling pressure has been the dominant trend recently.