Sui's mainnet went down for the second time in two days on Friday, May 30, 2026, after a botched fix from the previous day's five-hour outage triggered a fresh network halt — the latest in a string of reliability failures that has stripped the "Solana-killer" blockchain of roughly a fifth of its token value in a single week.

"Sui mainnet is currently experiencing a network stall. Network activity may be paused at this time," the team posted on X on Friday morning. About three hours later, they confirmed the network was back online — but not before publishing a post-mortem that laid bare the chain of failures.

"Both today's and yesterday's halts are due to the interaction of the 1.72 release, which introduced Address Balances, and gas charging logic," the team wrote on Friday. "Yesterday's implemented fix was an interim measure designed to restore functionality to the network while the Sui Core Team worked on a long-term solution."

The admission made clear that the team had shipped a patch on Thursday knowing it was incomplete. "The interim fix had a known issue with a low probability of causing a halt," they continued. "This morning, the network hit a variant of the known issue and halted."

Friday's stall was resolved when validators implemented what the team called a "long-term solution" — fully addressing the original bug introduced in the v1.72 release.

Two days, one root cause

Thursday's outage, which lasted more than five hours, began when the v1.72 update — which added a feature called Address Balances — exposed a conflict in the network's gas charging logic. Validators rolled out a patch that evening, restoring the chain. The Sui team presented it as a fix. It wasn't.

The interim patch contained a known defect. When the network hit a variant of that defect Friday morning, the chain halted again. The second outage lasted roughly three hours before the permanent fix — which engineers had been developing overnight — was deployed to validators.

No full technical post-mortem had been published as of filing time.

Token takes the hit

SUI was trading at around $0.89 at the time of publication, down 20% on the week. That decline places it among the five worst-performing assets in the top 100 coins by market cap over the same period, according to CoinGecko. The token is now more than 83% below its all-time high of $5.35, set in January 2025. Its market cap stands at approximately $3.6 billion.

The 20% weekly drop preceded the second outage — SUI had already been sliding on Thursday's news — but the Friday stall compounded the sentiment damage.

A recurring pattern

The back-to-back outages are not an anomaly in Sui's 2026 record. In January, the chain went dark for six hours after a similar network stall on its mainnet, requiring a comparable validator-coordinated fix to restore service. That makes at least three significant network stalls this year alone.

For a blockchain launched in 2023 by Mysten Labs — a team composed largely of former Meta engineers who built the Diem blockchain — the pattern is a credibility problem that reaches beyond the technical. Mysten raised a $300 million Series B in 2022 at a valuation of approximately $2 billion, with high throughput and predictable finality as central selling points.

The 'Solana-killer' credibility problem

The phrase "Solana-killer" has followed Sui since its launch, a marketing shorthand for chains promising to fix what ailed the high-throughput Solana ecosystem — most visibly, its history of major outages in 2021 and 2022 that froze transactions for hours at a time and rattled institutional confidence.

The irony of Sui's outage pattern is hard to miss. Solana was rebuilt and hardened through years of painful post-mortems; it has not experienced a comparable mainnet halt in recent cycles. Sui, pitching itself as the mature alternative, is now on its third significant stall of 2026 — and its second in 48 hours caused by a single software update.

The Decrypt article covering Friday's outage noted the parallel plainly: "Hailed as a 'Solana-killer,' the network has been plagued with some of the same issues as the speedy layer-1 network, which similarly dealt with major outages in the past."

What validators and the team did

The resolution followed the same playbook as previous Sui outages: the core team diagnosed the root cause, wrote a patch, coordinated with the validator set, and pushed the fix. The process works — both outages this week were resolved within hours — but it depends on tight coordination between Mysten's engineering team and the validators running the network. That coordination requires downtime to execute.

For a layer-1 pitching low latency and high finality as core value propositions, each stall tests how much tolerance its user base and developers have for intermittent unavailability. The 20% weekly token decline suggests that tolerance, at least in the short term, is limited.

A full post-mortem on the v1.72 issue had not been published as of Friday afternoon.

Sources: @SuiNetwork on X (May 29–30, 2026); Decrypt (May 30, 2026); CoinGecko (SUI price and ranking data)