New Zealand’s stock exchange kept trading Monday even as operator NZX’s website crashed again in what appears to be a resumption of cyber attacks that crippled the market last week.

See: Cyber attacks halt New Zealand stock exchange for fourth day

NZX.com has been down for much of the morning, preventing many investors from seeing company announcements and prices, but trading has continued since the 10 a.m. open in Wellington. When so-called distributed-denial-of-service attacks overwhelmed the website last week, NZX halted its cash markets out of concern about fair access to information.

NZX said today it has agreed on contingency arrangements with regulator the Financial Markets Authority for the release of, and access to, market announcements in the event of the website going offline. A spokesman declined to give more details. The feed of company announcements received by Bloomberg and other subscribers has remained available.

Justice Minister Andrew Little has expressed concern that NZX’s systems appear vulnerable after the cyber attacks from abroad disrupted trading four days running last week. He told Bloomberg Friday he was disappointed that an organization as important as the stock exchange had found itself so exposed, adding it was his expectation that NZX will step up its IT infrastructure and architecture and make sure it is better positioned to resist this type of activity in the future.

“NZX has been advised by independent cyber specialists that the attacks last week are among the largest, most well-resourced and sophisticated they have ever seen in New Zealand,” NZX said today. The company has been working with cyber defense experts from Akamai Technologies to implement additional measures, it said.

The attacks do not appear to have unnerved investors, who pushed the benchmark top-50 index to a record closing high on Friday. The S&P/NZX-50 was down 0.6% at 12,015 at 12:23 p.m. in Wellington.